diff --git a/air_monitor.service b/air_monitor.service
index 0d12725..0e11331 100644
--- a/air_monitor.service
+++ b/air_monitor.service
@@ -10,7 +10,6 @@ TimeoutStartSec=5
 User=nobody
 Group=nobody
 Restart=on-failure
-KillSignal=SIGQUIT
 Type=notify
 StandardError=syslog
 NotifyAccess=all
diff --git a/main.py b/main.py
index f227add..9748e5d 100644
--- a/main.py
+++ b/main.py
@@ -1,20 +1,29 @@
-from miio.airpurifier import AirPurifier, OperationMode, LedBrightness
-from miio.discovery import create_device
-from collections import namedtuple
-from datetime import datetime
-import time
-from influxdb import InfluxDBClient
-import json
 from systemd import daemon
+import errno
+import logging
+import signal
 import socket
+import sys
+import time
+from collections import namedtuple
+from multiprocessing import BoundedSemaphore, current_process, Process
+
+from influxdb import InfluxDBClient
+from miio.airpurifier import AirPurifier
+
 
 class Message(namedtuple('Message', ('measurement', 'time', 'tags', 'fields'))):
     __slots__ = ()
 
 
-class Atmosphere(namedtuple('Atmosphere', ('purifier_activated', 'purifier_fan_rpm', 'temperature', 'aqi', 'humidity'))):
-    __slots__ = ()
+class GracefulExit(Exception):
+    pass
 
+
+class Atmosphere(
+    namedtuple('Atmosphere', ('purifier_activated', 'purifier_fan_rpm', 'temperature', 'aqi', 'humidity'))):
+    __slots__ = ()
+    
     def __new__(cls, status):
         return super(Atmosphere, cls).__new__(cls,
                                               status.power == 'on',
@@ -25,26 +34,74 @@ class Atmosphere(namedtuple('Atmosphere', ('purifier_activated', 'purifier_fan_r
                                               )
 
 
-def getStat(dev):
+def signal_handler(signum, frame):
+    raise GracefulExit()
+
+
+def timerProvider():
     while True:
-        time.sleep(1)
-        yield time.time(), Atmosphere(dev.status())
+        yield time.time()
+        time.sleep(2.5)
+
+
+def sendPoints(idx, at, tags, readSem, sendSem, metric, dev):
+    proc = current_process()
+    logger = logging.getLogger('iter %d proc name %s id %s' % (idx, proc.name, proc.pid))
+    logger.info("start")
+    try:
+        readSem.acquire(timeout=15)
+        try:
+            fetch = dev.status()
+            info = Atmosphere(fetch)
+            message = Message('air', int(at * 1000000000), tags, info._asdict())
+        finally:
+            readSem.release()
+        
+        sendSem.acquire(timeout=15)
+        
+        try:
+            metric.write_points([message._asdict()])
+        finally:
+            sendSem.release()
+    except Exception as e:
+        logger.warning(e)
+    else:
+        logger.info('done')
 
 
 if __name__ == '__main__':
+    code = 0
     try:
-        metric = InfluxDBClient('db', database='core',
-                                use_udp=True, udp_port=8089)
-        air_addr=socket.gethostbyname("air")
-        #dev = create_device(air_addr,AirPurifier)
-        dev = AirPurifier(air_addr,'6e1e05b87d9f7cd10a3f8f43616896fa')
+        # Use signal handler to throw exception which can be caught to allow
+        # graceful exit.
+        logging.basicConfig(level=logging.INFO)
+        readSem = BoundedSemaphore(3)
+        sendSem = BoundedSemaphore(3)
+        
+        metric = InfluxDBClient('db', database='core', use_udp=True, udp_port=8089)
+        air_addr = socket.gethostbyname("air")
+        # dev = create_device(air_addr, AirPurifier)
+        dev = AirPurifier(air_addr, '6e1e05b87d9f7cd10a3f8f43616896fa')
+        
+        signal.signal(signal.SIGTERM, signal_handler)
+        signal.signal(signal.SIGINT, signal_handler)
         tags = {
             'source': 'mi_air_2',
             'position': 'center_room',
         }
         daemon.notify('READY=1')
-        for at, info in getStat(dev):
-            message = Message('air', int(at*1000000000), tags, info._asdict())
-            metric.write_points([message._asdict()])
+        for idx, at in enumerate(timerProvider()):
+            args = idx, at, tags, readSem, sendSem, metric, dev
+            p = Process(target=sendPoints, args=args)
+            p.daemon = True
+            p.start()
+    except GracefulExit as ge:
+        pass
+    except KeyboardInterrupt as ki:
+        pass
+    except Exception as e:
+        logging.error(e)
+        code = errno.EINVAL
     finally:
         daemon.notify('STOPPING=1')
+        sys.exit(code)