RE: Multi-Master Logical Replication

Hi hackers,

While analyzing about failure handling in the N-way logical replication,
I found that in previous PoC detaching API cannot detach a node which has failed.

I though lack of the feature was not suitable for testing purpose, so I would like to post a new version.
Also this patch was adjusted to new version of the infinite recursive patch[1]. 
0001-0004 were copied from the thread.

Note that LRG has been still implemented as the core feature.
We have not yet compared advantages for implementing as contrib modules.


[1]: https://www.postgresql.org/message-id/CALDaNm0PYba4dJPO9YAnQmuCFHgLEfOBFwbfidB1-pOS3pBCXA@mail.gmail.com

Best Regards,
Hayato Kuroda
FUJITSU LIMITED