I currently run a PSA (Primary, Secondary, Arbiter) deployment and thous only have two databearing nodes.
In case of a databearing node going down, read concern majority prevented the change stream to be read out of.
In MongoDB 4.2 it is now possible to disable the read concern majority for the replicaset and still use the change stream (See https://docs.mongodb.com/manual/release-notes/4.2/#change-stream).
I disabled read concern majority in my deployment and the change stream works as expected.
If I shut down the secondary node the change stream can't be read out of again.
Is this the expected behaviour? I would have assumed that with 4.2 a majority is not necessary anymore to read the change stream.
If that is the case, is there any way to read the change stream in a PSA deployment with only a minority of data bearing nodes?