Zookeeper how to set up and get watcher correctly

Watcher Setup is the most common development, need to understand some of the basic characteristics of watcher, for exists, GetData, getchild for the different operations of the node will receive different watcher information

state=-112 Session Timeout Status
State=-113 Authentication failed status
State= 1 Connection Setup
State= 2 (temporarily unclear how to understand this state, zoo_associating_state)
STATE=3 Connection established status
state= 999 no Connection status


Type=1 Creating node Events
type=2 Deleting node events
Type=3 Changing node Events
Type=4 child Node List Change event
Type=-1 Sessions Session event
Type=-2 Monitoring removed events

Changes to the parent node and changes to the grandchild node do not trigger watcher, and changes to the watcher itself and child nodes trigger watcher, as specified in the following table.

Operation	Method	Trigger Watcher	Watcher State	Watcher Type	Watcher Path
Create current node	GetData	X	X	X	X
	GetChildren	√	3	4	√
	Exists	X	X	X	X
Set current node	GetData	√	3	3	√
	GetChildren	X	X	X	X
	Exists	√	3	3	√
Delete current node	GetData	√	3	2	√
	GetChildren	√	3	2	√
	Exists	√	3	2	√
Create child node	GetData	X	X	X	X
	GetChildren	√	3	4	√
	Exists	X	X	X	X
Set child node	GetData	X	X	X	X
	GetChildren	X	X	X	X
	Exists	X	X	X	X
Delete child node	GetData	X	X	X	X
	GetChildren	√	3	4	√
	Exists	X	X	X	X
Restore connection	GetData	√	1	-1	X
	GetChildren	√	1	-1	X
	Exists	√	1	-1	X
Restore connection session not timed out	GetData	√	-112	-1	X
	GetChildren	√	-112	-1	X
	Exists	√	-112	-1	X
Restore Connection Session Timeout	GetData	√	3	-1	X
	GetChildren	√	3	-1	X
	Exists	√	3	-1	X

Note:x indicates no, √ indicates yes.
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Zookeeper how to set up and get watcher correctly