fixes for ekims suggestions

backfiller/backfiller/main.py

@@ -10,7 +10,6 @@ import signal
 import socket
 import urlparse
 import uuid
-from base64 import b64encode
 
 import argh
 import gevent.backdoor
@@ -40,8 +39,8 @@ hash_mismatches = prom.Counter(
 	['remote', 'channel', 'quality', 'hour'],
 )
 
-get_node_errors = prom.Counter(
-	'node_fetch_errors',
+node_list_errors = prom.Counter(
+	'node_list_errors',
 	'Number of errors fetching a list of nodes',
 	['filename', 'database'],
 )
@@ -126,8 +125,7 @@ def get_remote_segment(base_dir, node, channel, quality, hour, missing_segment,
 				f.write(chunk)
 				hash.update(chunk)
 
-		hash_str = b64encode(hash.digest(), "-_").rstrip("=")
-		if hash_str not in missing_segment:
+		if hash != common.parse_segment_path(missing_segment).hash:
 			logger.warn('Hash of segment {} does not match. Discarding segment'.format(missing_segment))
 			hash_mismatches.labels(remote=node, channel=channel, quality=quality, hour=hour).inc()
 			os.remove(temp_path)
@@ -244,8 +242,11 @@ class BackfillerManager(object):
 					failures += 1
 				delay = common.jitter(TIMEOUT * 2**failures)
 				self.logger.exception('Getting nodes failed. Retrying in {:.0f} s'.format(delay))
+				try:
 					host = [s.split('=')[-1] for s in self.connection.dsn.split() if 'host' in s][0]
-				get_node_errors.labels(filename=self.node_file, database=host).inc()
+				except Exception:
+					host = ''
+				node_list_errors.labels(filename=self.node_file, database=host).inc()
 				self.stopping.wait(delay)
 				continue
 			exisiting_nodes = set(self.workers.keys())