broneill
commented
5 years ago This is actually a pretty dangerous feature. A group is defined to ensure that enough copies of the data exist, and anything that automatically removes this redundancy creates a potential for data loss.
Group members which aren't available after awhile (configurable) are demoted to observers, facilitating easy replacement when hosts need to be replaced. If the demoted member becomes available again, it will need to ask the leader to update it's role back to what has been configured.
Only the leader can demote members, and it must also get confirmation from a majority that the member to demote is offline. If the member role is already observer, then none of this activity needs to be performed.