The following command lists all active EMR clusters in the current region:: aws emr list-clusters --active Output:: { "Clusters": [ { "Status": { "Timeline": { "ReadyDateTime": 1433200405.353, "CreationDateTime": 1433199926.596 }, "State": "WAITING", "StateChangeReason": { "Message": "Waiting after step completed" } }, "NormalizedInstanceHours": 6, "Id": "j-3SD91U2E1L2QX", "Name": "my-cluster" } ] }