The OpenStack identity service (Keystone) is one of the most significant services. It is responsible for providing identity, token management, authorization, and authentication. Many other OpenStack services depend on the Identity service. If there are any problems with the Identity service, it can cause other OpenStack functionalities to fail. Hence, it is vital to understand and know how to troubleshoot the Identity service.  

In most OpenStack installations, the default location of the log file for the Keystone service is:

/var/log/keystone/keystone.log

A different location for storing the log files can also be configured by editing the following file:

/etc/keystone/logging.conf