Cloud Load Balancers (LBaaS) can be used for numerous reasons, the most commonly that is for distrobuting traffic between multiple servers instead of using HAProxy or a dedicated Load Balancer, there are possitives and negatives to this however in my view load balancing as a service is a fantastic service, with some draw backs which I am sure I will detail in future posts. Anywho on to the actural reason you are reading this
During my previous time at Rackspace numerous users have had issues where their Managed Cloud Server would enter a failed status, this is commonly due to the post-build automation failing, the reasons for this can include novaclient not running, SSH running on a different port, package installation issues et al. This would commonly result in the user having to contact Rackspace to resolve the issue, while you should continue to contact Rackspace about this to ensure that the managed software is correctly installed, the below would allow you to update the metadata that is set due to this failure.