1. What impacts on the data guard environment if the far sync standby is down ?
If the Far sync instance is not available then the redo data will not be transferred to standby any more, that is the disadvantage, Again still you can configure with flexible architecture. That means when the far sync instance is not available you can use "ALTERNATE" attribute in the LOG_ARCHIVE_DEST_n.
So that when the far sync instance is not available, the primary can be able to send redo data directly to the standby database.
2. Is it possible to make more servers running as far sync standby?
Yes, you can configure but you need to have proper plan why you need more servers?
If the primary and standby is too far and the far sync you will be creating near to the primary, This will works until the primary and standby are doing good. But the picture is going to change after the switchover of the configuration, Means now standby becomes primary and primary becomes standby. In this situtaion far sync will be near to the new standby but not near to the new primary. In these cases to ensure highly flexible architecutre of far sync you can have two far sync instances. Where one far sync is near to the primary and the other far sync near to the standby. In thus configuration there are no more issues.
So overall you can configure more than one far sync.
Hope this answer helps you.
Also recently i have presented session on 12c Data Guard : Far sync and new features , You can take a look and it may helps you
Message was edited by: CKPT
Thanks for your reply.
I have another doubt is there any direct connection between Primary Database and Physical Standby database in case of far sync standby ?
If you have configured ALTERNATE location, then when far sync is unavailable then it can communicate to standby (or) else the primary communication is always far sync.