No Upgrade from v2 or v3 RA Web Service Agent
The RA Web Service REST Agent is based on different libs/solution than v3.x. V4.x uses CXF for SOAP Jobs, while v3 used AXIS2. There is no automatic upgrade from Web Service v2 or v3 Agent to Web Service v4 Agent. All connection and Job objects have to be defined/upgraded manually in v4. Web Service Agent v4 solution doesn't replace the Web Service Agent v2 or v3 solution, it needs to be installed on as a separately installed RA Agent. Consequently, a combination of Web Service v2, v3, and v4 Agents can be run in parallel within one Automation Engine or CA Automic Applications Manager system.