When used with scrapy, use it with Scrapy Scheduler provided by scrapy-frontera. Scrapy scheduler provided by Frontera is not supported
See usage instructions at module and class docstrings at backend.py.
Package also installs a convenient command line tool for hubstorage frontier handling and manipulation: hcfpal.py. It supports dumping, count, deletion, moving, listing, etc.
Another tool provided is hcfmanager.py. It facilitates the scheduling of consumer spider jobs.