1, Zookeeper data types: a small amount of a hierarchical directory structure data +
Zookeeper comprise a hierarchical directory structure, and each has a unique path identifier znode, znode may contain data and sub-nodes.
Wherein Znode data may have multiple versions, if the data contains a plurality of versions of the path, the path in the query data, need to bring version.
2, Zookeeper node types: Node temporary (ephemeral), node lasting (persistent), the order of the nodes (sequence). When you create a node type is determined, it can not be modified later.
(1) temporary node after the client session, zookeeper will delete the temporary node, and the temporary node can not have child nodes.
(2) persistent node does not depend on the client's session, only the client explicitly want to remove the persistent node, it will be deleted.
3, Zookeeper role: leader leader, follower follower, observer observer