During the map phase of the selection step, the generator rejects many (usually most of) items for various reasons:
- not yet time for a refetch (returned by the fetch scheduler)
- generator score too low
- status does not match restrict status
- Jexl expression not matched
and some more. It would be useful if the reasons are counted and logged, esp. when the CrawlDb gets bigger and multiple options to restrict the selection are used.