old_contents: """Delete all documents every second forever"""
  
  __author__ = 'tunnell'
  
  import sys
  import time
  import json
  
  import pymongo
  
  
  if __name__ == "__main__":
      c = pymongo.MongoClient()
  
      db = c.data
      collection = db.test
  
      # Key to sort by so we can use an index for quick query
      sort_key = [("_id", pymongo.ASCENDING),
                  ("triggertime", pymongo.ASCENDING)]
  
      # Index for quick query
      collection.create_index(sort_key, dropDups=True)
  
      # Loop until Ctrl-C or error
      while (1):
          # This try-except catches Ctrl-C and error
          try:
              # Non-sense query that is in index
              query = {"triggertime": {'$gt': 0}}
  
              # Perform query
              cursor = collection.find(query,
                                       fields=['triggertime']).sort(sort_key)
  
              # Are we using index for quick queries?  Not always true if there
              # are no documents in the collection...
              print('Using index:', cursor.explain()['indexOnly'])
  
              # Stats on how the delete worked.  Write concern (w=1) is on.
              print(json.dumps(collection.remove(query),
                               indent=4,
                               sort_keys=True,
                               w=1))
  
              # Wait a second so we don't query the DB too much
              time.sleep(1)
  
          except pymongo.errors.OperationFailure as e:
              print('MongoDB error:', e)
  
          except KeyboardInterrupt:
              print("Ctrl-C caught so exiting.")
              sys.exit(0)
  
new_contents: """Delete all documents every second forever"""
  
  __author__ = 'tunnell'
  
  import sys
  import time
  import json
  
  import pymongo
  
  
  if __name__ == "__main__":
      c = pymongo.MongoClient()
  
      db = c.data
      collection = db.test
  
      # Key to sort by so we can use an index for quick query
      sort_key = [("_id", pymongo.ASCENDING),
                  ("triggertime", pymongo.ASCENDING)]
  
      # Index for quick query
      collection.create_index(sort_key, dropDups=True)
  
      # Loop until Ctrl-C or error
      while (1):
          # This try-except catches Ctrl-C and error
          try:
              # Non-sense query that is in index
              query = {"triggertime": {'$gt': 0}}
  
              # Perform query
              cursor = collection.find(query,
                                       fields=['triggertime']).sort(sort_key)
  
              # Are we using index for quick queries?  Not always true if there
              # are no documents in the collection...
              print('Using index:', cursor.explain()['indexOnly'])
  
              # Stats on how the delete worked. Write concern is on.
              print(json.dumps(collection.remove(query),
                               indent=4,
                               sort_keys=True))
  
              # Wait a second so we don't query the DB too much
              time.sleep(1)
  
          except pymongo.errors.OperationFailure as e:
              print('MongoDB error:', e)
  
          except KeyboardInterrupt:
              print("Ctrl-C caught so exiting.")
              sys.exit(0)
  
subject: Write concern bug fix in constantly deleting DB. It's on by default and w=1 does nothing.