In Mac OS and Python 2.7, Scrapy has an issue, which can not read request.seen file. So when you use JOBDIR setting to pause and resume task, the duplicate filter does not work. You have to change the source code of Scapy Path: /Library/Python/2.7/site-packages/scrapy/dupefilter.py class RFPDupeFilter(BaseDupeFilter): """Request Fingerprint duplicates filter""" def __init__ ( self , path= None , debug= False ): self .file = None self .fingerprints = set () self .logdupes = True self .debug = debug if path: self .file = open (os.path.join(path, 'requests.seen' ), 'a+' ) self.file.seek(0) self .fingerprints.update(x.rstrip() for x in self .file) Red line is added. Reference: http://stackoverflow.com/questions/14639936/how-to-read-from-file-opened-in-a-mode