RFS[11]: Client instance is standby database instead of primary

Server: RHEL6

Oracle DB version: 12.1

In my Primary Alert log i'm seeing RFS messages writing frequently like below

Primary alert log :

RFS[10]: Assigned to RFS process (PID:16586)

RFS[10]: Database mount ID mismatch [0x6666ae9b:0x666707e4] (1718005403:171802260)

RFS[10]: Client instance is standby database instead of primary

Tue Feb 19 16:10:14 2019

RFS[11]: Assigned to RFS process (PID:174682)

RFS[11]: Database mount ID mismatch [0x6666ae9b:0x666707e4] (1718005403:1718028260)

RFS[11]: Client instance is standby database instead of primary

 After researching further and according to Oracle (Doc ID 1450132.1)

Cause:

It's due to my Standby database is sending ARCH logs back to my Primary site (RAC exadata machine) (don’t know how this was happening) and causing these messages writing to my Primary alert log  and to fix this I’ve to find and remove "dest_" parameter which is pointing back to primary site

On standby site

SQL> sho parameter dest_2

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

db_create_online_log_dest_2          string

log_archive_dest_2                   string      service=myprod_prim ARCH SYNC NO

                                                              AFFIRM delay=0 OPTIONAL reopen=15 register

SQL> sho parameter dest_state_2

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

log_archive_dest_state_2             string      ENABLE

Yes i see my dest_2 is pointing to Primary and it is ENABLED so remove this parameter (OR) DEFER it 

FIX:

SQL> ALTER SYSTEM SET log_archive_dest_2='' scope=both;

System altered.

Now i see  NO messages are writing in alert log