This chapter details the OpenStack Identity service configuration options. For installation prerequisites and step-by-step walkthroughs, see the OpenStack Installation Guide for your distribution (docs.openstack.org) and Cloud Administrator Guide.

Identity supports a caching layer that is above the configurable subsystems, such as token or assignment. The majority of the caching configuration options are set in the [cache] section. However, each section that has the capability to be cached usually has a caching option that will toggle caching for that specific section. By default, caching is globally disabled. Options are as follows: Current functional backends are: dogpile.cache.memcached - Memcached backend using the standard python-memcached library dogpile.cache.pylibmc - Memcached backend using the pylibmc library dogpile.cache.bmemcached - Memcached using python-binary-memcached library. dogpile.cache.redis - Redis backend dogpile.cache.dbm - Local DBM file backend dogpile.cache.memory - In-memory cache, not suitable for use outside of testing as it does not cleanup it's internal cache on cache expiration and does not share cache between processes. This means that caching and cache invalidation will not be consistent or reliable. dogpile.cache.mongo - MongoDB as caching backend.

The Identity service is configured in the /etc/keystone/keystone.conf file. The following tables provide a comprehensive list of the Identity service options.