ASE 16.0 sp02 as primary at host_1
ASE 15.7.0 as catalog ( RSSD) for Rep server version 15.7.1, both at host_2
ASE 16 sp02 as replicated at host_3
Environment : WS pairs local (same site and no routes)
-Could we keep using ASE catalog version at version 15.7 and RS 15.7.1 for both ASE 16 primary and replicated?
-If we choose to upgrade ASE catalog ( 15.7 ) to 16 , which would be recommended steps for this operation, assuming ASE 16 can act as RS 15.7.1 catalog?
Would it be enough to :
At host_2 with ASE 15.7 catalog:
-backup system db's plus RSSD
-install a new ASE 16 at host_2
-load system db's backups plus RSSD into ASE 16
Not clear when you say load system database into ASE 16.
If it is a new host + new instance then you will need to create the new RSSD (at least a shell for the load) with matching device sizes.
If it is in place upgrade from 15.7 to 16 then there is no need to load any system databases.
RSSD will get upgraded in the process.
As Mark has given an excellent and detailed feedback make sure that replication pipeline is shut off during the RSSD upgrade. And operation sequence is followed as suggested.