Deep Security Relay (DSR) Agent creates alert ID 190 "Relay Update Service Unavailable" if a Deep Security Agent (DSA) or a Deep Security Virtual Appliance (DSVA) tries to retrieve updates from the DSR within twenty (20) minutes after the DSR received its own update.
This is an expected behavior because the DSR Agent shuts down itself and blocks any connectivity. The main reason is that the DSR and the nginx.exe file should be exclusively available for its own update process. This process can take up to 20 minutes.
To resolve the issue, make sure that the scheduled update for DSA or DSVA is set to at least 20 minutes after the scheduled DSR update.