bug: regression: wrap metric calls in thread handler

The metric calls were blocking. It was recommended that they be wrapped
by a discrete thread handler.

Issue: #1408

autopush/metrics.py

@@ -93,20 +93,26 @@ def _make_tags(self, tags):
 
     def increment(self, name, count=1, tags=None, **kwargs):
         threads.deferToThread(
-            self._client.incr(self._prefix_name(name), count,
-                              tags=self._make_tags(tags))
+            self._client.incr,
+            self._prefix_name(name),
+            count,
+            tags=self._make_tags(tags)
         )
 
     def gauge(self, name, count, tags=None, **kwargs):
         threads.deferToThread(
-            self._client.gauge(self._prefix_name(name), count,
-                               tags=self._make_tags(tags))
+            self._client.gauge,
+            self._prefix_name(name),
+            count,
+            tags=self._make_tags(tags)
         )
 
     def timing(self, name, duration, tags=None, **kwargs):
         threads.deferToThread(
-            self._client.timing(self._prefix_name(name), value=duration,
-                                tags=self._make_tags(tags))
+            self._client.timing,
+            self._prefix_name(name),
+            value=duration,
+            tags=self._make_tags(tags)
         )
 
 

autopush/websocket.py

@@ -91,7 +91,7 @@
 from autopush.exceptions import MessageOverloadException, ItemNotFound
 from autopush.noseplugin import track_object
 from autopush.protocol import IgnoreBody
-from autopush.metrics import IMetrics, make_tags  # noqa
+from autopush.metrics import IMetrics  # noqa
 from autopush.ssl import AutopushSSLContextFactory  # noqa
 from autopush.utils import (
     parse_user_agent,
@@ -895,7 +895,7 @@ def process_notifications(self):
         self.ps._check_notifications = False
         self.ps._more_notifications = True
 
-        d = self.deferToThread(self.webpush_fetch())
+        d = self.deferToThread(self.webpush_fetch)
         d.addCallback(self.finish_notifications)
         d.addErrback(self.error_notification_overload)
         d.addErrback(self.trap_cancel)
@@ -1319,7 +1319,9 @@ def process_nack(self, data):
                        user_agent=self.ps.user_agent, message_id=str(version),
                        code=code, **self.ps.raw_agent)
         mcode = code if code in NACK_CODES else 0
-        self.metrics.increment('ua.command.nack', tags=make_tags(code=mcode))
+        self.metrics.increment(
+            'ua.command.nack',
+            tags=self.metrics.make_tags(code=mcode))
         self.ps.stats.nacks += 1
 
     def check_missed_notifications(self, results, resume=False):
@@ -1373,8 +1375,9 @@ def send_notification(self, update):
     def emit_send_metrics(self, notif):
         if notif.topic:
             self.metrics.increment("ua.notification.topic")
-        self.metrics.increment('ua.message_data', notif.data_length,
-                               tags=make_tags(source=notif.source))
+        self.metrics.increment(
+            'ua.message_data', notif.data_length,
+            tags=self.metrics.make_tags(source=notif.source))
 
 
 class PushServerFactory(WebSocketServerFactory):