25968684_ZooKeeper_JMX_s__their_names_and_description_Description
[MBean] DataTree [MBean Object Name] InMemoryDataTree [Description] 
Statistics on the in memory znode database, also operations to access finer (and more computationally intensive) statistics on the data (such as ephemeral count). InMemoryDataTrees are children of ZooKeeperServer nodes.
ZooKeeper JMX
Description