A persistent operation: reissue a watched operation every time the watch fires, applying safe retries when possible.
A persistent operation: reissue a watched operation every time the watch fires, applying safe retries when possible.
The returned Activity is asynchronous: watches aren't reissued when the Activity is no longer observed.
ZkSession wraps a ZooKeeper client which automatically reconnects upon session expiry. Cribbed from https://github.com/twitter/finagle/blob/develop/finagle-serversets/src/main/scala/com/twitter/finagle/serverset2/ZkSession.scala