Documents and entire web sites can go offline. Write a cron script that periodically examines all copy URLs to ensure that they still exist. Keep track of which URLs have failed, with a failure count and failure age. Add rules to delete copies from the database that have failed for too long.
Documents and entire web sites can go offline. Write a cron script that periodically examines all copy URLs to ensure that they still exist. Keep track of which URLs have failed, with a failure count and failure age. Add rules to delete copies from the database that have failed for too long.