The Identity Service provides identity, token, catalog, and policy services. It consists of: keystone Web Server Gateway Interface (WSGI) service. Can be run in a WSGI-capable web server such as Apache httpd to provide the Identity Service. The service and administrative APIs are run as separate instances of the WSGI service. Identity Service functions. Each has a pluggable back end that allows different ways to use the particular service. Most support standard back ends like LDAP or SQL. keystone-all. Starts both the service and administrative APIs in a single process. Using federation with keystone-all is not supported. keystone-all is deprecated in favor of the WSGI service. The Identity Service also maintains a user that corresponds to each service, such as, a user named nova for the Compute service, and a special service tenant called service. For information about how to create services and endpoints, see the OpenStack Admin User Guide.