The execution order is from lower to higher (0, 1,2).
In config.yml the value doesn’t depend of the order in which they appear, but they depends on order parameter in the authc block
kerberos_auth_domain:
http_enabled: false
transport_enabled: false
order: 6
http_authenticator:
type: kerberos
challenge: true
config:
# If true a lot of kerberos/security related debugging output will be logged to standard out
krb_debug: false
# If true then the realm will be stripped from the user name
strip_realm_from_principal: true
authentication_backend:
type: noop