Cluster manager task throttling

The first line of defense is to implement mechanisms in the caller nodes to avoid task overload on the cluster manager. However, even with those mechanisms in place, the cluster manager needs a built-in way to protect itself: cluster manager task throttling.

To turn on cluster manager task throttling, you need to set throttling limits. The cluster manager uses the throttling limits to determine whether to reject a task.

The cluster manager rejects a task based on its type. For any incoming task, the cluster manager evaluates the total number of tasks of the same type in the pending task queue. If this number exceeds the threshold for this task type, the cluster manager rejects the incoming task. Rejecting a task does not affect tasks of a different type. For example, if the cluster manager rejects a put-mapping task, it can still accept a subsequent create-index task.

You can set throttling limits by specifying them in the cluster_manager.throttling.thresholds object and updating the . The setting is dynamic, so you can change the behavior of this feature without restarting your cluster.

By default, throttling is disabled for all task types.

The request has the following format:

Supported task types

The following task types are supported:

create-index
update-settings
cluster-update-settings
auto-create
delete-index
delete-dangling-index
create-data-stream
remove-data-stream
rollover-index
index-aliases
remove-index-template
create-component-template
remove-component-template
create-index-template-v2
remove-index-template-v2
put-pipeline
delete-pipeline
create-persistent-task
finish-persistent-task
remove-persistent-task
update-task-state
put-script
delete-script
put-repository
delete-snapshot
update-snapshot-state
restore-snapshot
cluster-reroute-api

Example request

The following request sets the throttling threshold for the put-mapping task type to 100:

PUT _cluster/settings
{
  "persistent": {
    "cluster_manager.throttling.thresholds": {
      "put-mapping": {
        "value": 100
      }
    }
  }

Set the threshold to -1 to disable throttling for a task type.