Zookeeper average client session timeout

[#1]

Hello Team,

Consider i have a client which is negotiating a timeout from the ZK server.

I have observed that 0x36e18413b196cfc  is the session id and i could see that ZK is terminating the connection after 23,419 seconds ??? Could anyone suggest why ?? 

2020-01-30 01:03:23,762 - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:ZooKeeperServer@861] - Client attempting to renew session 0x36e18413b196cfc at /xx.xx.xx.xx:37952
2020-01-30 01:03:23,762 - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:Learner@108] - Revalidating client: 0x36e18413b196cfc
2020-01-30 01:03:23,762 - INFO [QuorumPeer[myid=1]/0.0.0.0:2181:ZooKeeperServer@617] - Established session 0x36e18413b196cfc with negotiated timeout 10000 for client /xx.xx.xx.xx:37952
EndOfStreamException: Unable to read additional data from client sessionid 0x36e18413b196cfc, likely client has closed socket
2020-01-30 07:33:42,962 - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxn@1033] - Closed socket connection for client //xx.xx.xx.xx:37952 which had sessionid 0x36e18413b196cfc

[#2]

This is on HDP 2.6.5, ZK version : 3.4.6.2

[#3 · Accepted solution]

The following values are used based on ZooKeeper settings:

minSessionTimeout = ticktime * 2,  maxSessionTimeout=ticktime * 20

If no Session Timeouts are set in the client, the server will use tickTime*2. Hence, any session which establishes to ZooKeeper, will have this value as a minimum timeout. 
Likewise, if there are no SessionTimout set, the maximum value will be tickTime*20. Hence, any session which establishes to ZooKeeper will have this value as a maximum timeout. 

The sessionTimeout cannot be less than minSessionTimeout (ticktime * 2) or greater than maxSessionTimeout (ticktime * 20).