Many ZooKeeper properties are not configurable in zoo.cfg. If configured in zoo.cfg, QuorumPeerConfig parse logic will pre append "zookeeper" which is not the same property used in code. So a property with a name abc.xyz becomes zookeeper.abc.xyz
Bellow are properties which can not configured in zoo.cfg, can only be configured using java system properties.
This jira targets to make these properties configurable in zoo.cfg as well.