scanner: lower log level

Warnings can make think the operator that sbws is not working,
while it's normal that some measurements fail.
Resultdump already logs at info level what succcess and what fails.
Keep these logs at debug level.

sbws/core/scanner.py

@@ -84,9 +84,9 @@ def measure_rtt_to_server(session, conf, dest, content_length):
         success, data = timed_recv_from_server(session, dest, random_range)
         if not success:
             # data is an exception
-            log.warning('While measuring the RTT to %s we hit an exception '
-                        '(does the webserver support Range requests?): %s',
-                        dest.url, data)
+            log.debug('While measuring the RTT to %s we hit an exception '
+                      '(does the webserver support Range requests?): %s',
+                      dest.url, data)
             return None
         assert success
         # data is an RTT
@@ -114,9 +114,9 @@ def measure_bandwidth_to_server(session, conf, dest, content_length):
         success, data = timed_recv_from_server(session, dest, random_range)
         if not success:
             # data is an exception
-            log.warning('While measuring the bandwidth to %s we hit an '
-                        'exception (does the webserver support Range '
-                        'requests?): %s', dest.url, data)
+            log.debug('While measuring the bandwidth to %s we hit an '
+                      'exception (does the webserver support Range '
+                      'requests?): %s', dest.url, data)
             return None
         assert success
         # data is a download time
@@ -170,8 +170,8 @@ def measure_relay(args, conf, destinations, cb, rl, relay):
     # Pick a destionation
     dest = destinations.next()
     if not dest:
-        log.warning('Unable to get destination to measure %s %s',
-                    relay.nickname, relay.fingerprint[0:8])
+        log.debug('Unable to get destination to measure %s %s',
+                  relay.nickname, relay.fingerprint[0:8])
         return None
     # Pick a relay to help us measure the given relay. If the given relay is an
     # exit, then pick a non-exit. Otherwise pick an exit.
@@ -189,7 +189,7 @@ def measure_relay(args, conf, destinations, cb, rl, relay):
             circ_fps = [relay.fingerprint, helper.fingerprint]
     if not helper:
         # TODO: Return ResultError of some sort
-        log.warning('Unable to pick a 2nd hop to help measure %s %s',
+        log.debug('Unable to pick a 2nd hop to help measure %s %s',
                     relay.nickname, relay.fingerprint[0:8])
         return None
     assert helper
@@ -198,7 +198,7 @@ def measure_relay(args, conf, destinations, cb, rl, relay):
     our_nick = conf['scanner']['nickname']
     circ_id, reason = cb.build_circuit(circ_fps)
     if not circ_id:
-        log.warning('Could not build circuit involving %s', relay.nickname)
+        log.debug('Could not build circuit involving %s', relay.nickname)
         msg = 'Unable to complete circuit'
         return [
             ResultErrorCircuit(relay, circ_fps, dest.url, our_nick, msg=msg),
@@ -210,9 +210,9 @@ def measure_relay(args, conf, destinations, cb, rl, relay):
     # still help us measure
     is_usable, usable_data = dest.is_usable(circ_id, s, cb.controller)
     if not is_usable:
-        log.warning('When measuring %s %s the destination seemed to have '
-                    'stopped being usable: %s', relay.nickname,
-                    relay.fingerprint[0:8], usable_data)
+        log.debug('When measuring %s %s the destination seemed to have '
+                  'stopped being usable: %s', relay.nickname,
+                  relay.fingerprint[0:8], usable_data)
         cb.close_circuit(circ_id)
         # TODO: Return a different/new type of ResultError?
         msg = 'The destination seemed to have stopped being usable'
@@ -224,8 +224,8 @@ def measure_relay(args, conf, destinations, cb, rl, relay):
     # FIRST: measure RTT
     rtts = measure_rtt_to_server(s, conf, dest, usable_data['content_length'])
     if rtts is None:
-        log.warning('Unable to measure RTT to %s via relay %s %s',
-                    dest.url, relay.nickname, relay.fingerprint[0:8])
+        log.debug('Unable to measure RTT to %s via relay %s %s',
+                  dest.url, relay.nickname, relay.fingerprint[0:8])
         cb.close_circuit(circ_id)
         # TODO: Return a different/new type of ResultError?
         msg = 'Something bad happened while measuring RTTs'
@@ -236,8 +236,8 @@ def measure_relay(args, conf, destinations, cb, rl, relay):
     bw_results = measure_bandwidth_to_server(
         s, conf, dest, usable_data['content_length'])
     if bw_results is None:
-        log.warning('Unable to measure bandwidth to %s via relay %s %s',
-                    dest.url, relay.nickname, relay.fingerprint[0:8])
+        log.debug('Unable to measure bandwidth to %s via relay %s %s',
+                  dest.url, relay.nickname, relay.fingerprint[0:8])
         cb.close_circuit(circ_id)
         # TODO: Return a different/new type of ResultError?
         msg = 'Something bad happened while measuring bandwidth'