#1681 add copy() in metrics() to avoid thread safety issues (#1682)

Author: emeric254

kafka/consumer/group.py

@@ -903,10 +903,10 @@ def metrics(self, raw=False):
             releases without warning.
         """
         if raw:
-            return self._metrics.metrics
+            return self._metrics.metrics.copy()
 
         metrics = {}
-        for k, v in six.iteritems(self._metrics.metrics):
+        for k, v in six.iteritems(self._metrics.metrics.copy()):
             if k.group not in metrics:
                 metrics[k.group] = {}
             if k.name not in metrics[k.group]:

kafka/producer/kafka.py

@@ -716,10 +716,10 @@ def metrics(self, raw=False):
             releases without warning.
         """
         if raw:
-            return self._metrics.metrics
+            return self._metrics.metrics.copy()
 
         metrics = {}
-        for k, v in six.iteritems(self._metrics.metrics):
+        for k, v in six.iteritems(self._metrics.metrics.copy()):
             if k.group not in metrics:
                 metrics[k.group] = {}
             if k.name not in metrics[k.group]: