When accessing Rally, the following error is shown when attempting to log into the application:
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.
The URL shown in the address bar starts with the following:
Release : SAAS
Component : AGILE CENTRAL
This indicates that there is a problem with the SSO service on the Rally side which may prevent you from logging into the application via SSO. Rally based authentication will still function in this scenario for users on the exceptions list or users in subscriptions configured for hybrid authentication. If this is an option for you, you may still log in with those non-SSO credentials at https://rally1.rallydev.com.
Please open a support case so we can investigate the issue.
keywords: 503, login, connect, sso.rallydev.com/sp/ACS.saml2