opensearch-docs-cn/_im-plugin/ism/settings.md

layout	title	parent	nav_order
default	Settings	Index State Management	4

ISM settings

We don't recommend changing these settings; the defaults should work well for most use cases.

Index State Management (ISM) stores its configuration in the .opendistro-ism-config index. Don't modify this index without using the ISM API operations.

All settings are available using the OpenSearch _cluster/settings operation. None require a restart, and all can be marked persistent or transient.

Setting	Default	Description
plugins.index_state_management.enabled	True	Specifies whether ISM is enabled or not.
plugins.index_state_management.job_interval	5 minutes	The interval at which the managed index jobs are run.
plugins.index_state_management.jitter	0.6	A delay that is added to a job's base run time to prevent a surge of activity from all indices at the same time. A value of 0.6 means 60% of run time is added to the base run time. For example, if you have a base run time of 30 minutes, a value of 0.6 means 18 minutes gets added to your run time, for a total of 48 minutes. Maximum is 1, which means an additional run time of 100%. This maximum cannot exceed plugins.jobscheduler.jitter_limit, which also has a default of 0.6. For example, if plugins.index_state_management.jitter is set to 0.8, ISM uses plugins.jobscheduler.jitter_limit of 0.6 instead.
plugins.index_state_management.coordinator.sweep_period	10 minutes	How often the routine background sweep is run.
plugins.index_state_management.coordinator.backoff_millis	50 milliseconds	The backoff time between retries for failures in the ManagedIndexCoordinator (such as when we update managed indices).
plugins.index_state_management.coordinator.backoff_count	2	The count of retries for failures in the ManagedIndexCoordinator.
plugins.index_state_management.history.enabled	True	Specifies whether audit history is enabled or not. The logs from ISM are automatically indexed to a logs document.
plugins.index_state_management.history.max_docs	2,500,000	The maximum number of documents before rolling over the audit history index.
plugins.index_state_management.history.max_age	24 hours	The maximum age before rolling over the audit history index.
plugins.index_state_management.history.rollover_check_period	8 hours	The time between rollover checks for the audit history index.
plugins.index_state_management.history.rollover_retention_period	30 days	How long audit history indices are kept.
plugins.index_state_management.allow_list	All actions	List of actions that you can use.

Audit history indices

If you don't want to disable ISM audit history or shorten the retention period, you can create an index template to reduce the shard count of the history indices:

PUT _index_template/ism_history_indices
{
  "index_patterns": [
    ".opendistro-ism-managed-index-history-*"
  ],
  "template": {
    "settings": {
      "number_of_shards": 1,
      "number_of_replicas": 0
    }
  }
}