diff --git a/oml/nodes.py b/oml/nodes.py
index ea89cf7..d16b402 100644
--- a/oml/nodes.py
+++ b/oml/nodes.py
@@ -542,8 +542,6 @@ class Nodes(Thread):
             self.queue('pull')
 
     def _pull(self):
-        if not state.sync_enabled or settings.preferences.get('downloadRate') == 0:
-            return
         if state.activity and state.activity.get('activity') == 'import':
             return
         self._pulling = True
diff --git a/oml/server.py b/oml/server.py
index d0e997d..89401d0 100644
--- a/oml/server.py
+++ b/oml/server.py
@@ -6,6 +6,7 @@ import sys
 import signal
 import time
 
+from tornado.httpserver import HTTPServer
 from tornado.ioloop import IOLoop
 from tornado.web import StaticFileHandler, Application
 
@@ -70,6 +71,7 @@ def shutdown():
         logger.debug('shutdown downloads')
         state.downloads.join()
     logger.debug('shutdown http_server')
+    state.http_server.stop()
     if state.tasks:
         logger.debug('shutdown tasks')
         state.tasks.join()
@@ -133,9 +135,8 @@ def run():
     ]
 
     setup.create_db()
-    http_server = Application(handlers, **options)
-    max_buffer_size = 2*1024*1024*1024
-    http_server.listen(settings.server['port'], settings.server['address'], max_buffer_size=max_buffer_size)
+    http_server = HTTPServer(Application(handlers, **options))
+    http_server.listen(settings.server['port'], settings.server['address'])
 
     if PID:
         with open(PID, 'w') as pid:
diff --git a/oml/state.py b/oml/state.py
index 4768e7b..7f63690 100644
--- a/oml/state.py
+++ b/oml/state.py
@@ -8,7 +8,6 @@ node = False
 online = False
 tasks = False
 downloads = False
-sync_enabled = True
 tor = False
 update = False
 shutdown = False
diff --git a/oml/update.py b/oml/update.py
index 566d66b..c265f63 100644
--- a/oml/update.py
+++ b/oml/update.py
@@ -333,9 +333,7 @@ class Update(Thread):
     def install(self):
         while update_available():
             self.status('Downloading...')
-            max_retry = 5
-            while max_retry > 0 and not download():
-                max_retry -= 1
+            while not download():
                 self.status('Download failed, retrying...')
                 time.sleep(5)
                 self.status('Downloading...')
diff --git a/oml/websocket.py b/oml/websocket.py
index 7e468f2..466adeb 100644
--- a/oml/websocket.py
+++ b/oml/websocket.py
@@ -57,10 +57,11 @@ class Handler(WebSocketHandler):
 
     def post(self, event, data):
         message = json_dumps([event, data])
+        main = IOLoop.instance()
         if self.ws_connection is None:
             self.on_close()
         else:
-            state.main.add_callback(lambda: self.write_message(message))
+            main.add_callback(lambda: self.write_message(message))
 
 def trigger_event(event, data):
     #if len(state.websockets):
diff --git a/requirements-shared.txt b/requirements-shared.txt
index 2edce59..934cfb4 100644
--- a/requirements-shared.txt
+++ b/requirements-shared.txt
@@ -1,5 +1,5 @@
-requests==2.21.0
-tornado==5.1.1
+requests==2.9.1
+tornado==4.3
 chardet
 html5lib
 #ox>=2.0.666
@@ -8,5 +8,5 @@ python-stdnum==1.2
 PyPDF2==1.25.1
 pysocks
 stem
-sqlitedict==1.6.0
+sqlitedict==1.4.0
 zeroconf