The 4.3 release removes support for logs-only replication clients. Use of the DB_REP_LOGSONLY flag to the DB_ENV->rep_start() should be replaced with the DB_REP_CLIENT flag.
The 4.3 release adds two new arguments to the DB_ENV->rep_elect() method, nvotes and flags. The nvotes argument sets the required number of replication group members that must participate in an election in order for a master to be declared. For backward compatibility, set the nvotes argument to 0. The flags argument is currently unused and should be set to 0. See DB_ENV->rep_elect() method or "Replication Elections" for more information.
In the 4.3 release it is no longer necessary to do a database environment hot backup to initialize a replication client. All that is needed now is for the client to join the replication group. Berkeley DB will perform an internal backup from the master to the client automatically and will run recovery on the client to bring it up to date with the master.