The IdP returned role Distinguished Name (DN) 'cn=splunk_dns,ou=groups,dc=foo,dc=bar', which matches configured role map Common Name (CN) splunk_dns'. This role DN has now been locked to the role map CN, using the 'dns' role. Future assertions that contain this CN but do not match the locked DN will be rejected.
Seeing multiple messages like this, every time we login. Is something wrong with our config? how to stop this notification...
I think this is expected behavior. We just upgraded our environments (7.3.5 --> 8.1.3) and are now seeing these messages/notifications. Check to see if you have "lockRoleToFullDN=true" set in authentication.conf:
splunk/bin/splunk btool authentication list --debug | grep lockRoleToFullDN
When this parameter is set to true Splunk will capture the full DN of a CN, the first time it sees it, and insert it under the [lockedRoleToFullDNMap_SAML] stanza in etc/system/local/authentication.conf.
I believe you can disable these notifications by setting "lockRoleToFullDN=false". However, I have not tested this just yet.