Discovery and gateway settings

The following are settings related to discovery and local gateway.

To learn more about static and dynamic settings, see Configuring OpenSearch.

Discovery settings

The discovery process is used when a cluster is formed. It consists of discovering nodes and electing a cluster manager node. For comprehensive information about discovery and cluster formation settings, see Discovery and cluster formation settings.

• discovery.find_peers_interval_during_decommission (Static, time unit): Sets the time interval between attempts to find all peers when a node is in decommissioned state. When a node is being decommissioned, it continues to discover other nodes at this interval to maintain cluster membership information during the decommission process. This helps ensure proper coordination during controlled node removal. Default is 120s (2 minutes). Minimum is 1000ms.

• discovery.unconfigured_bootstrap_timeout (Static, time unit): Sets the timeout period for unconfigured bootstrap process during cluster formation. This setting controls how long a node will wait during the bootstrap phase when the cluster is not properly configured (e.g., when cluster.initial_cluster_manager_nodes is not set). After this timeout, the node will proceed with bootstrap operations or fail appropriately. This setting helps prevent nodes from waiting indefinitely in unconfigured states. Default is 3s. Minimum is 1ms.

Gateway settings

The local gateway stores on-disk cluster state and shard data that is used when a cluster is restarted. The following local gateway settings are supported:

• gateway.recover_after_data_nodes (Static, integer): The minimum number of data nodes that must be running after a full cluster restart before recovery can begin.
  • Default: 0
  • Recommendation: Set to a significant portion of the data nodes—approximately 50–70% of the total data nodes—to avoid premature recovery.
• gateway.expected_data_nodes (Static, integer): The expected number of data nodes in the cluster. When all are present, recovery of local shards can start immediately.
  • Default: 0
  • Recommendation: Set this to the actual number of data nodes in your cluster so that recovery can start immediately once all data nodes are running.
• gateway.recover_after_time (Static, time unit): The maximum amount of time to wait until recovery if the expected data node count hasn’t been reached. After this time, recovery proceeds.
  • Default: 5m if expected_data_nodes or recover_after_nodes is set. Otherwise disabled.
  • Recommendation: Set slightly above your typical node join time; larger clusters often need longer to recover and are tuned based on observed startup behavior.

• gateway.write_dangling_indices_info (Static, Boolean): Controls whether OpenSearch writes information about dangling indexes to disk during cluster state persistence. When enabled, the system maintains metadata about indexes that exist on disk but are not part of the current cluster state, which can help with recovery and troubleshooting scenarios. Default is true.

• gateway.auto_import_dangling_indices (Static, Boolean): Controls whether OpenSearch automatically imports dangling indexes discovered during cluster startup. Dangling indexes are indexes that exist on disk but are not part of the current cluster state, typically left behind after improper cluster shutdowns or node removals. When enabled, these orphaned indexes are automatically imported back into the cluster state during startup. When disabled, dangling indexes remain on disk but are not automatically imported, requiring manual intervention through the Dangling Indices API. This setting helps recover potentially lost data but should be used carefully to avoid importing unwanted indiexes. Default is true.