The AisTrack server is currently not persisting the AIS overview, which it provides. The result is, that it will take several hours after a server restart to rebuild the AIS overview in areas (e.g. Arctic) where AIS messages are primarily received from satellites. Some sort of persistence is needed in order to reload the AIS overview after a server restart.
It seems that a solution already exists to persist/backup and reload the TargetTracker data. The TargetTrackerFileBackupService class from the dma-dk/AisLib project can do just that.
The AisTrack server is currently not persisting the AIS overview, which it provides. The result is, that it will take several hours after a server restart to rebuild the AIS overview in areas (e.g. Arctic) where AIS messages are primarily received from satellites. Some sort of persistence is needed in order to reload the AIS overview after a server restart.