When performing rolling upgrades, esp when a cluster is running in mixed mode where some nodes are < 7.0 and some are 7.0, XDCR does not prevent the users from activating collection-related modes/toggles.
In the interest of safety, XDCR should enforce implicit mapping and not allow users to edit anything collection-related until it is confirmed that source cluster is fully upgraded.
Also, it may make sense to check target cluster compatibility before allowing collection-related feature in replication settings to be set.
|For Gerrit Dashboard: MB-45926
|MB-45926: prevent explicit mode until cluster is fully upgraded