Fix async.py is_exporter context (#909)

Author: lzchen

.github/CODEOWNERS

@@ -3,4 +3,3 @@
 
 # For anything not explicitly taken by someone else:
 *       @census-instrumentation/global-owners @c24t @hectorhdzg @lzchen @reyang @songy23 @victoraugustolls
-

contrib/opencensus-ext-azure/opencensus/ext/azure/common/exporter.py

@@ -65,6 +65,7 @@ def __init__(self, src, dst):
 
     def run(self):  # pragma: NO COVER
         # Indicate that this thread is an exporter thread.
+        # Used to suppress tracking of requests in this thread
         execution_context.set_is_exporter(True)
         src = self.src
         dst = self.dst

contrib/opencensus-ext-azure/opencensus/ext/azure/log_exporter/__init__.py

@@ -79,6 +79,7 @@ def __init__(self, src, dst):
 
     def run(self):
         # Indicate that this thread is an exporter thread.
+        # Used to suppress tracking of requests in this thread
         execution_context.set_is_exporter(True)
         src = self._src
         dst = self._dst

opencensus/common/transports/async_.py

@@ -92,6 +92,8 @@ def _thread_main(self):
         Pulls pending data off the queue and writes them in
         batches to the specified tracing backend using the exporter.
         """
+        # Indicate that this thread is an exporter thread.
+        # Used to suppress tracking of requests in this thread
         execution_context.set_is_exporter(True)
         quit_ = False
 
@@ -142,8 +144,6 @@ def start(self):
             self._thread = threading.Thread(
                 target=self._thread_main, name=_WORKER_THREAD_NAME)
             self._thread.daemon = True
-            # Indicate that this thread is an exporter thread. Used for
-            # auto-collection.
             self._thread.start()
             atexit.register(self._export_pending_data)
 

opencensus/common/transports/sync.py

@@ -13,11 +13,16 @@
 # limitations under the License.
 
 from opencensus.common.transports import base
+from opencensus.trace import execution_context
 
 
 class SyncTransport(base.Transport):
     def __init__(self, exporter):
         self.exporter = exporter
 
     def export(self, datas):
+        # Used to suppress tracking of requests in export
+        execution_context.set_is_exporter(True)
         self.exporter.emit(datas)
+        # Reset the context
+        execution_context.set_is_exporter(False)

opencensus/metrics/transport.py

@@ -66,6 +66,7 @@ def func(*aa, **kw):
 
     def run(self):
         # Indicate that this thread is an exporter thread.
+        # Used to suppress tracking of requests in this thread
         execution_context.set_is_exporter(True)
         super(PeriodicMetricTask, self).run()