compass-adapters/chef/cookbooks/compass-rally/files/default/scenarios/authenticate/keystone.json

{
    "Authenticate.keystone": [
        {
            "runner": {
                "type": "constant",
                "times": 3,
                "concurrency": 2
            },
            "context": {
                "users": {
                    "tenants": 3,
                    "users_per_tenant": 3
                }
            }
        }
    ]
}