1. Zonemgr should support adding/deleting zones dynamically.
2. Make zonemgr has customizable configurations for LOWERBOUND_REFRESH, LOWERBOUND_RETRY, MAX_TRANSFER_TIMEOUT, REFRESH_OFFSET, RETRY_OFFSET, EXPIRED_OFFSET, and/or jitter?
3. There should be one way to see the current counters/timers and other data for each zone managed by zonemgr.
+4. There should be one way to turn off zonemgr.(Does user really need it? not sure what's the purpose of user)