simple manual fail over for IDP

[jehan procaccia]

Hello,
I did read 
https://wiki.shibboleth.net/confluence/display/SHIB2/IdPClusterIntro
and before getting into deep high availability or load balancing
I just want to enable a single entry point to my shibboleth SSO service 
so that
I can  shutdown one IDP server for maintenance/upgrade and manually 
promote the other one to serve requests and vice versa.
Example:
               sso.domain.fr
                         |
                     /      \
                    /        \
             IDP1        IDP2

most of the time , sso.domain.fr redirects to IDP1, when a maintenance 
occurs on IDP1, sso.domain.fr redirects to IDP2.
does the IDP[1,2] must have the same metadata, share a common entityIDs 
and bindings Locations ?
Is this simple scenary already documented somewhere ?

Thanks.