Solution : https://service.sap.com/sap/support/notes/915482 (SAP Service marketplace login required)
Key words : 
/os standby db server failover automation reason, import parameter new_db_con specifies, automate db2 maintenance operations, single sap abap instances, import parameterswitch_all_app_servers controls, import parameter new_host, ini configuration file, maximum wait time, s_db2_dbadm authorization profile, ccms transport sapk640ocd
Related Notes : 
       
| 570650 | DB2/390: Availability of RFC SDK on Linux for zSeries | 
| 427748 | DB2-z/OS: CCMS corrections (6.10, 6.20, 6.40, 7.x) | 
| 413708 | Current RFC library | 
| 119496 | OS/390: Availability of the RFC SDK | 
| 81737 | DB2-z/OS: APAR List |