I want to be able to access a very recent copy of my master Redis server keys. It doesn't have to be completely up to date as I will be polling the read only copy but I don't want the transactions and Lua scripts I run on the master instance to block on the read only instance as I SCAN through the keys on my read only instance.
Can anyone confirm/deny this behaviour?
It won't block the slaves from anything, but while the master is busy processing your logic replication will be stopped. Once the logic ends (possibly generating writes), replication will resume with the previous buffered contents and the new ones (if any).