CUE Zipline sends a heartbeat request at regular intervals to all the services it is connected to (the Content Store, CUE Print and DC-X). If it does not get a response then the service is marked as currently unavailable. The heartbeat section of the configuration file contains the following two properties:

period (optional, default: 500)

The interval between heartbeats, specified in seconds.

timeout (optional, default: 5)

The length of time CUE Zipline waits for a response before marking a service as unavailable, specified in seconds.