keystone db missing in HA scenarios

in HA scenarios with the series of patches to get galera / percona working

keystone commands still fail, causing the puppet run to error out with a series of Errors like:

Debug: Executing '/usr/bin/keystone --os-endpoint http://172.29.75.155:35357/v2.0/ role-list'
Error: /Stage[main]/Keystone::Roles::Admin/Keystone_role[_member_]: Could not evaluate: Execution of '/usr/bin/keystone --os-endpoint http://172.29.75.155:35357/v2.0/ role-list' returned 1: An unexpected error prevented the server from fulfilling your request. (HTTP 500)

these are caused by missing tables in the keystone db. A manual

keystone-manage db_sync

resolves and then subsequent puppet runs complete cleanly