backfiller: Don't backfill segments that only differ from existing segment by 1ms

In the wild we've seen different servers get timestamps that differ by 1ms for segments
that are otherwise identical - same content, same duration.

The allowable fudge factor for segments is already 10ms, so having timing be 1ms different
between servers shouldn't cause any problems.
Worst case, there's a slight chance you'll get an adjacent frame when picking a cut point / thumbnail.

backfiller/backfiller/main.py

@@ -16,7 +16,6 @@ import argh
 import gevent.backdoor
 import gevent.pool
 import prometheus_client as prom
-from requests.adapters import HTTPAdapter
 
 import common
 from common import dateutil
@@ -24,10 +23,8 @@ from common import database
 from common.requests import InstrumentedSession
 from common.segments import list_segment_files, unpadded_b64_decode
 
-# Wraps all requests in some metric collection and connection pooling
+# Wraps all requests in some metric collection
 requests = InstrumentedSession()
-adapter = HTTPAdapter(pool_maxsize=100)
-requests.mount('https://', adapter)
 
 segments_backfilled = prom.Counter(
 	'segments_backfilled',
@@ -518,7 +515,6 @@ class BackfillerWorker(object):
 					EPSILON = 0.001
 					local_infos = []
 					for path in local_segments:
-						path = os.path.join(channel, quality, hour, path)
 						try:
 							local_infos.append(common.parse_segment_path(path))
 						except ValueError as e:

downloader/downloader/main.py

@@ -15,7 +15,6 @@ import gevent.backdoor
 import gevent.event
 import prometheus_client as prom
 import requests
-import requests.adapters
 from monotonic import monotonic
 
 import common
@@ -336,8 +335,6 @@ class StreamWorker(object):
 		# This worker's SegmentGetters will use its session by default for performance,
 		# but will fall back to a new one if something goes wrong.
 		self.session = common.requests.InstrumentedSession()
-		adapter = requests.adapters.HTTPAdapter(pool_maxsize=100)
-		self.session.mount('https://', adapter)
 		# Map cache is a simple cache to avoid re-downloading the same map URI for every segment,
 		# since it's generally the same but may occasionally change.
 		# We expect the map data to be very small so there is no eviction here.