diff --git a/cache_warming/cache_warming.py b/cache_warming/cache_warming.py
index e094d4a..3416b56 100644
--- a/cache_warming/cache_warming.py
+++ b/cache_warming/cache_warming.py
@@ -13,11 +13,13 @@
 import json
 import os
 import socket
+import sys
 import dns.exception
 import dns.resolver
 
 hit_log = {}
 last_fetch = datetime.min
+verbose = False
 TOP_N = 50
 FETCH_INTERVAL = 60  # seconds
 UDP_SERVER_PATH = '/tmp/dns_query_log_socket'
@@ -34,6 +36,8 @@
     log: Dictionary of top requested hosts with host key and tuple value
          containing most recent hit time and hit count.
   """
+  if verbose:
+    print 'Saving hosts in %s.' % HOSTS_JSON_PATH
   d = os.path.dirname(HOSTS_JSON_PATH)
   if not os.path.exists(d):
     os.makedirs(d)
@@ -47,6 +51,8 @@
   Loads dictionary with host key and tuple value containing most recent hit
   time and hit count as hit_log if it exists.
   """
+  if verbose:
+    print 'Loading hosts from %s.' % HOSTS_JSON_PATH
   if os.path.isfile(HOSTS_JSON_PATH):
     with open(HOSTS_JSON_PATH, 'r') as hosts_json:
       global hit_log
@@ -64,6 +70,8 @@
             '[Unix time] [host name]'.
   """
   time, _, host = qry.partition(' ')
+  if verbose:
+    print 'Received query for %s.' % host
   if host in hit_log:
     hit_log[host] = (hit_log[host][0] + 1, time)
   else:
@@ -103,9 +111,13 @@
   if len(hosts) > TOP_N:
     hosts = hosts[:TOP_N]
   for host in hosts:
+    if verbose:
+      print 'Fetching %s.' % host
     try:
       my_resolver.query(host)
     except dns.exception.DNSException:
+      if verbose:
+        print 'Failed to fetch %s.' % host
       del hit_log[host]
       hosts.remove(host)
 
@@ -121,14 +133,20 @@
   return sorted(hit_log, key=hit_log.get, reverse=True)
 
 
-def warm_cache():
+def warm_cache(port, server):
   """Warms cache with predetermined number of most requested hosts.
 
   Sorts hosts in hit log by hit count, fetches predetermined
   number of top requested hosts, updates last fetch time.
+
+  Args:
+    port: Port to which to send queries (default is 53).
+    server: Alternate nameservers to query (default is None).
   """
+  if verbose:
+    print 'Warming cache.'
   sorted_hosts = sort_hit_log()
-  fetch(sorted_hosts, args.port, args.server)
+  fetch(sorted_hosts, port, server)
   global last_fetch
   last_fetch = datetime.now()
 
@@ -144,11 +162,15 @@
                       help='port to which to send queries (default is 53).')
   parser.add_argument('-s', '--server', nargs='*', type=str,
                       help='alternate nameservers to query (default is None).')
+  parser.add_argument('-v', '--verbose', action='store_true')
   return parser.parse_args()
 
 
 if __name__ == '__main__':
+  sys.stdout = os.fdopen(1, 'w', 1)
+  sys.stderr = os.fdopen(2, 'w', 1)
   args = set_args()
+  verbose = args.verbose
   load_hosts()
 
   server_address = UDP_SERVER_PATH
@@ -161,10 +183,12 @@
   sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
   sock.bind(server_address)
   os.chmod(server_address, 0o777)
+  if verbose:
+    print 'Set up socket at %s.' % HOSTS_JSON_PATH
 
   while 1:
     diff = datetime.now() - last_fetch
     if diff.total_seconds() > 60:
-      warm_cache()
+      warm_cache(args.port, args.server)
     data = sock.recv(128)
     process_query(data)
diff --git a/cmds/statcatcher.cc b/cmds/statcatcher.cc
index 184c725..64db2b6 100644
--- a/cmds/statcatcher.cc
+++ b/cmds/statcatcher.cc
@@ -119,6 +119,8 @@
     if (recvsize < 0) {
       perror("Failed to receive data on socket.\n");
       exit(1);
+    } else {
+      fprintf(stderr, "received %d bytes\n", recvsize);
     }
     pkt.resize(recvsize);
 
diff --git a/waveguide/waveguide.py b/waveguide/waveguide.py
index cbc9fe8..87324c3 100755
--- a/waveguide/waveguide.py
+++ b/waveguide/waveguide.py
@@ -907,7 +907,8 @@
     wifiblaster.enable         Enable WiFi performance measurement.
     wifiblaster.interval       Average time between automated measurements in
                                seconds, or 0 to disable automated measurements.
-    wifiblaster.measureall     Unix time at which to measure all clients.
+    wifiblaster.measureall     Unix time at which to measure all clients, or 0
+                               to disable measureall requests.
     wifiblaster.onassociation  Enable WiFi performance measurement after clients
                                associate.
 
@@ -938,6 +939,20 @@
     except ValueError:
       return None
 
+  def _GetParameters(self):
+    """Reads and returns all parameters if valid, or Nones."""
+    duration = self._ReadParameter('duration', float)
+    enable = self._ReadParameter('enable', self._StrToBool)
+    fraction = self._ReadParameter('fraction', int)
+    interval = self._ReadParameter('interval', float)
+    measureall = self._ReadParameter('measureall', float)
+    onassociation = self._ReadParameter('onassociation', self._StrToBool)
+    size = self._ReadParameter('size', int)
+    if (duration > 0 and enable and fraction > 0 and interval >= 0
+        and measureall >= 0 and size > 0):
+      return (duration, fraction, interval, measureall, onassociation, size)
+    return (None, None, None, None, None, None)
+
   def _SaveResult(self, line):
     """Save wifiblaster result to the status file for that client."""
     g = re.search(MACADDR_REGEX, line)
@@ -975,23 +990,18 @@
     """Return the time of the next measurement event."""
     return self._next_measurement_time
 
-  def Measure(self, interface, client):
+  def Measure(self, interface, client, duration, fraction, size):
     """Measures the performance of a client."""
-    enable = self._ReadParameter('enable', self._StrToBool)
-    duration = self._ReadParameter('duration', float)
-    fraction = self._ReadParameter('fraction', int)
-    size = self._ReadParameter('size', int)
-    if enable and duration > 0 and fraction > 0 and size > 0:
-      RunProc(callback=self._HandleResults,
-              args=[WIFIBLASTER_BIN, '-i', interface, '-d', str(duration),
-                    '-f', str(fraction), '-s', str(size),
-                    helpers.DecodeMAC(client)])
+    RunProc(callback=self._HandleResults,
+            args=[WIFIBLASTER_BIN, '-i', interface, '-d', str(duration),
+                  '-f', str(fraction), '-s', str(size),
+                  helpers.DecodeMAC(client)])
 
   def MeasureOnAssociation(self, interface, client):
     """Measures the performance of a client after association."""
-    onassociation = self._ReadParameter('onassociation', self._StrToBool)
+    (duration, fraction, _, _, onassociation, size) = self._GetParameters()
     if onassociation:
-      self.Measure(interface, client)
+      self.Measure(interface, client, duration, fraction, size)
 
   def Poll(self, now):
     """Polls the state machine."""
@@ -1005,29 +1015,33 @@
       # Inter-arrival times in a Poisson process are exponentially distributed.
       # The timebase slip prevents a burst of measurements in case we fall
       # behind.
-      self._next_measurement_time = now + random.expovariate(1 / interval)
+      self._next_measurement_time = now + random.expovariate(1.0 / interval)
 
-    interval = self._ReadParameter('interval', float)
-    if interval <= 0:
+    # Read parameters.
+    (duration, fraction, interval, measureall, _, size) = self._GetParameters()
+
+    # Handle automated mode.
+    if interval > 0:
+      if self._interval != interval:
+        # Enable or change interval.
+        StartMeasurementTimer(interval)
+      elif now >= self._next_measurement_time:
+        # Measure a random client.
+        StartMeasurementTimer(interval)
+        try:
+          (interface, client) = random.choice(self._GetAllClients())
+        except IndexError:
+          pass
+        else:
+          self.Measure(interface, client, duration, fraction, size)
+    else:
       Disable()
-    elif self._interval != interval:
-      # Enable or change interval.
-      StartMeasurementTimer(interval)
-    elif now >= self._next_measurement_time:
-      # Measure a random client.
-      StartMeasurementTimer(interval)
-      try:
-        (interface, client) = random.choice(self._GetAllClients())
-      except IndexError:
-        pass
-      else:
-        self.Measure(interface, client)
 
-    measureall = self._ReadParameter('measureall', float)
+    # Handle measureall request.
     if time.time() >= measureall and measureall > self._last_measureall_time:
       self._last_measureall_time = measureall
       for (interface, client) in self._GetAllClients():
-        self.Measure(interface, client)
+        self.Measure(interface, client, duration, fraction, size)
 
     # Poll again in at most one second. This allows parameter changes (e.g. a
     # measureall request or a long interval to a short interval) to take effect
diff --git a/waveguide/wifiblaster_controller_test.py b/waveguide/wifiblaster_controller_test.py
index 6b562b1..9e300f2 100755
--- a/waveguide/wifiblaster_controller_test.py
+++ b/waveguide/wifiblaster_controller_test.py
@@ -17,6 +17,7 @@
 
 import glob
 import os
+import random
 import shutil
 import sys
 import tempfile
@@ -102,6 +103,7 @@
   d = tempfile.mkdtemp()
   old_wifiblaster_dir = waveguide.WIFIBLASTER_DIR
   waveguide.WIFIBLASTER_DIR = tempfile.mkdtemp()
+  oldexpovariate = random.expovariate
   oldpath = os.environ['PATH']
   oldtime = time.time
 
@@ -110,6 +112,7 @@
     return faketime[0]
 
   try:
+    random.expovariate = lambda lambd: random.uniform(0, 2 * 1.0 / lambd)
     time.time = FakeTime
     os.environ['PATH'] = 'fake:' + os.environ['PATH']
     sys.path.insert(0, 'fake')
@@ -141,11 +144,6 @@
       WriteConfig('measureall', '0')
       WriteConfig('size', '1470')
 
-      # Disabled. No measurements should be run.
-      print manager.GetState()
-      for t in xrange(0, 100):
-        wc.Poll(t)
-
       def CountRuns():
         try:
           v = open('fake/wifiblaster.out').readlines()
@@ -155,16 +153,24 @@
           os.unlink('fake/wifiblaster.out')
           return len(v)
 
-      CountRuns()  # get rid of any leftovers
+      # Get rid of any leftovers.
+      CountRuns()
+
+      # Disabled.
+      # No measurements should be run.
+      print manager.GetState()
+      for t in xrange(0, 100):
+        wc.Poll(t)
       wvtest.WVPASSEQ(CountRuns(), 0)
 
+      # Enabled.
       # The first measurement should be one cycle later than the start time.
       # This is not an implementation detail: it prevents multiple APs from
       # running simultaneous measurements if measurements are enabled at the
       # same time.
       WriteConfig('enable', 'True')
       wc.Poll(100)
-      wvtest.WVPASSGE(wc.NextMeasurement(), 100)
+      wvtest.WVPASSGT(wc.NextMeasurement(), 100)
       for t in xrange(101, 200):
         wc.Poll(t)
       wvtest.WVPASSGE(CountRuns(), 1)
@@ -183,20 +189,16 @@
         wc.Poll(t)
       wvtest.WVPASSGE(CountRuns(), 1)
 
-      # Run the measurement at t=400 to restart the timer.
-      wc.Poll(400)
-      wvtest.WVPASSGE(CountRuns(), 0)
-
       # Next poll should be in at most one second regardless of interval.
-      wvtest.WVPASSLE(wc.NextTimeout(), 401)
+      wvtest.WVPASSLE(wc.NextTimeout(), 400)
 
-      # Enabled with longer average interval.  The change in interval should
+      # Enabled with shorter average interval.  The change in interval should
       # trigger a change in next poll timeout.
       WriteConfig('interval', '0.5')
       old_to = wc.NextMeasurement()
-      wc.Poll(401)
+      wc.Poll(400)
       wvtest.WVPASSNE(old_to, wc.NextMeasurement())
-      for t in xrange(402, 500):
+      for t in xrange(401, 500):
         wc.Poll(t)
       wvtest.WVPASSGE(CountRuns(), 1)
 
@@ -218,6 +220,7 @@
                               manager.GetState().assoc[0].mac)
       wvtest.WVPASSEQ(CountRuns(), 1)
   finally:
+    random.expovariate = oldexpovariate
     time.time = oldtime
     shutil.rmtree(d)
     os.environ['PATH'] = oldpath