zookeeper server role
Leader
(1) The only scheduler and processor of transaction requests to ensure the sequence of cluster transaction processing
(2) The scheduler of each service within the cluster
Follower
(1) Process the client's non-transaction request and forward the transaction request to the Leader server
(2) Participate in the voting of the transaction request Proposal
(3) Participate in the leader election vote
Observer
(1) A server role introduced after version 3.0, which improves the non-transaction processing capabilities of the cluster without affecting the transaction processing capabilities of the cluster.
(2) Processes non-transaction requests from the client and forwards transaction requests to the Leader server
(3) Does not participate Any form of voting