Why Red Hat Satellite 6.0 Beta webui fails with 500 error?

Issue

• Unable to access Satellite webui and fails with 500 error:

127.0.0.1 - - [10/Jul/2014:09:24:14 -0400] "POST /pulp/api/v2/repositories/search/ HTTP/1.1" 500 531 "-" "Ruby"
127.0.0.1 - - [10/Jul/2014:09:24:14 -0400] "GET /katello/sync_management HTTP/1.1" 500 441 "https://satellite.fqdn/hosts" "Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Firefox/24.0"
500 Internal Server Error (RestClient::InternalServerError)
{"http_request_method": "POST", "exception": null, "error_message": "find_one operation failed on pulp_database.users: database connection still down after 3 tries", "_href": "/pulp/api/v2/repositories/search/", "http_status": 500, "error": {"code": "PLP0000", "data": {}, "description": "find_one operation failed on pulp_database.users: database connection still down after 3 tries", "sub_errors": []}, "args": ["find_one operation failed on pulp_database.users: database connection still down after 3 tries"], "traceback": null}