Major version upgrades + Replication - Mailing list pgsql-admin

We have a setup with 1 primary, a synchronous replica and two asynchronous replicas all running on PostgreSQL 9.1. I'm in the progress of planning an upgrade to 9.4 so that we can make use of cascading replication.

The process I'm planning currently is: 

At this point will the secondary replicate from the primary correctly or do I need to

rsync everything across again? 

I understand that the 9.1 replicas won't be able to replicate from 9.4 until they're upgraded; however I'm I'm hoping to essentially pg_upgrade all the replicas and avoid having to rsync the upgraded master to all it's replicas.

Thanks,

Rob