**To create an Amazon DocumentDB cluster instance** The following ``create-db-instance`` example code creates the instance ``sample-cluster-instance-2`` in the Amazon DocumentDB cluster ``sample-cluster``. :: aws docdb create-db-instance \ --db-cluster-identifier sample-cluster \ --db-instance-class db.r4.xlarge \ --db-instance-identifier sample-cluster-instance-2 \ --engine docdb Output:: { "DBInstance": { "DBInstanceStatus": "creating", "PendingModifiedValues": { "PendingCloudwatchLogsExports": { "LogTypesToEnable": [ "audit" ] } }, "PubliclyAccessible": false, "PreferredBackupWindow": "00:00-00:30", "PromotionTier": 1, "EngineVersion": "3.6.0", "BackupRetentionPeriod": 3, "DBInstanceIdentifier": "sample-cluster-instance-2", "PreferredMaintenanceWindow": "tue:10:28-tue:10:58", "StorageEncrypted": false, "Engine": "docdb", "DBClusterIdentifier": "sample-cluster", "DBSubnetGroup": { "Subnets": [ { "SubnetAvailabilityZone": { "Name": "us-west-2a" }, "SubnetStatus": "Active", "SubnetIdentifier": "subnet-4e26d263" }, { "SubnetAvailabilityZone": { "Name": "us-west-2c" }, "SubnetStatus": "Active", "SubnetIdentifier": "subnet-afc329f4" }, { "SubnetAvailabilityZone": { "Name": "us-west-2d" }, "SubnetStatus": "Active", "SubnetIdentifier": "subnet-53ab3636" }, { "SubnetAvailabilityZone": { "Name": "us-west-2b" }, "SubnetStatus": "Active", "SubnetIdentifier": "subnet-991cb8d0" } ], "DBSubnetGroupDescription": "default", "SubnetGroupStatus": "Complete", "VpcId": "vpc-91280df6", "DBSubnetGroupName": "default" }, "DBInstanceClass": "db.r4.xlarge", "VpcSecurityGroups": [ { "Status": "active", "VpcSecurityGroupId": "sg-77186e0d" } ], "DBInstanceArn": "arn:aws:rds:us-west-2:123456789012:db:sample-cluster-instance-2", "DbiResourceId": "db-XEKJLEMGRV5ZKCARUVA4HO3ITE" } } For more information, see `Adding an Amazon DocumentDB Instance to a Cluster <https://docs.aws.amazon.com/documentdb/latest/developerguide/db-instance-add.html>`__ in the *Amazon DocumentDB Developer Guide*.