invoke sample: from dmsinventory.inventory import DMSInventory

inventory = DMSInventory()

inventory.getnamebyaid(accountid)

inventory.getusrbyip(accountid,usr)

For the beheavior: first check the cache , if cache missing , retrieve from zookeeper. at the same time, add the watcher for the corresponding node , then the node will exist in cache and update by watcher. if can not get the node finally , will return None