comment udpate
use getData() instead of exists() to avoid leaving unneeded watchers which is a type of resource leak
use getData() instead of exists() to avoid leaving unneeded watchers which is a type of resource leak. However, this might have
performance affects. Therefore, added system proprety "curator-path-children-cache-use-exists" to use the old behavior. i.e.
add -Dcurator-path-children-cache-use-exists=true or call System.setProperty("curator-path-children-cache-use-exists", "true") to
use the old behavior of calling exists() instead.