The server polling feature addresses the issue of unreachable Security Agents not receiving timely notifications about component updates and changes to agent settings. This feature is independent of the heartbeat feature.
With the server polling feature:
Security Agents automatically initiate connection with the Apex One server at regular intervals. When the server detects that polling took place, it treats the agent as "Unreachable/Online".
Security Agents connect to one or several of their update sources to download any updated components and apply new agent settings. If the Apex One server or an Update Agent is the primary update source, agents obtain both components and new settings. If the source is not the Apex One server or Update Agent, agents only obtain the updated components and then connect to the Apex One server or Update Agent to obtain the new settings.