Keystone is an OpenStack project that provides
Identity, Token, Catalog and Policy services for use specifically by
projects in the OpenStack family. When a client obtains a token from
Keystone, that token has a validity period before
it expires. However even after it is marked expired, it is kept in the
MySQL database of OpenStack. This can create issues if your
environment is passing out a lot of tokens and can cause the token table
to grow.
To prevent this infinite growth, you can implement
the following command in a cron to clean up the expired tokens within
the MySQL DB:
keystone-manage token-flush
