Your Logon Analyzer Clients will always collect data, also when they cannot, for any reason, contact their Logon Analyzer Server. If they can't make contact, they'll cache the information and send it at first contact. Once they've uploaded their cached info to their Logon Analyzer Server, their cache is cleared.
This has as a consequence that you can reboot, or otherwise disable your Logon Analyzer Server without consequence for as far as logging and rule implementation are concerned.
It also means that you can install the Logon Analyzer Client to computers in your Active Directory before you install a Logon Analyzer Server.
Clients will send an update to the server at least once every ten minutes. If you reboot or restart the server, it will take at most ten minutes before the server is totally up to date again.