Log stats for fallback relays separately

Fallback relays get much more load than other relays when client churn,
so keep track of their stats separately.

simulator.py

@@ -154,15 +154,23 @@ class Simulator:
         relaystats = network.PerfStatsStats(True)
         relaybstats = network.PerfStatsStats(True)
         relaynbstats = network.PerfStatsStats(True)
+        relayfbstats = network.PerfStatsStats(True)
         for r in self.relays:
             logging.debug("%s", r.perfstats)
             relaysent += r.perfstats.bytes_sent
             relayrecv += r.perfstats.bytes_received
             relaystats.accum(r.perfstats)
             if r.perfstats.is_bootstrapping:
-                relaybstats.accum(r.perfstats)
+                if r.is_fallbackrelay:
+                    self.statslogger.error(
+                        "ERROR: fallback relay is bootstrapping?")
+                else:
+                    relaybstats.accum(r.perfstats)
             else:
-                relaynbstats.accum(r.perfstats)
+                if r.is_fallbackrelay:
+                    relayfbstats.accum(r.perfstats)
+                else:
+                    relaynbstats.accum(r.perfstats)
         totsent += relaysent
         totrecv += relayrecv
         clistats = network.PerfStatsStats()
@@ -188,6 +196,7 @@ class Simulator:
         numclients = len(self.clients)
         self.statslogger.info("Dirauths %s", dirastats)
         self.statslogger.info("Relays %s", relaystats)
+        self.statslogger.info("Relays(FB) %s", relayfbstats)
         self.statslogger.info("Relays(B) %s", relaybstats)
         self.statslogger.info("Relays(NB) %s", relaynbstats)
         self.statslogger.info("Clients %s", clistats)