refactor: Use ContextVarsScopeManager instead of AsyncioScopeManager.

As we support now only the Python runtime >= 3.7, the usage of the ContextVarsScopeManager as Tracer's scope manager is indicated to provide automatic Span propagation from parent coroutines, tasks and scheduled in event loop callbacks to their children.

Signed-off-by: Paulo Vital <[email protected]>

Author: pvital

instana/instrumentation/asyncio.py

@@ -7,34 +7,38 @@
 from ..log import logger
 from ..singletons import async_tracer
 from ..configurator import config
+from opentracing.scope_managers.contextvars import no_parent_scope
+from opentracing.scope_managers.constants import ACTIVE_ATTR
 
 try:
     import asyncio
 
     @wrapt.patch_function_wrapper('asyncio','ensure_future')
     def ensure_future_with_instana(wrapped, instance, argv, kwargs):
         if config['asyncio_task_context_propagation']['enabled'] is False:
-            return wrapped(*argv, **kwargs)
+            with no_parent_scope():
+                return wrapped(*argv, **kwargs)
 
         scope = async_tracer.scope_manager.active
         task = wrapped(*argv, **kwargs)
 
         if scope is not None:
-            async_tracer.scope_manager._set_task_scope(scope, task=task)
+            setattr(task, ACTIVE_ATTR, scope)
 
         return task
 
     if hasattr(asyncio, "create_task"):
         @wrapt.patch_function_wrapper('asyncio','create_task')
         def create_task_with_instana(wrapped, instance, argv, kwargs):
             if config['asyncio_task_context_propagation']['enabled'] is False:
-                return wrapped(*argv, **kwargs)
+                with no_parent_scope():
+                    return wrapped(*argv, **kwargs)
 
             scope = async_tracer.scope_manager.active
             task = wrapped(*argv, **kwargs)
 
             if scope is not None:
-                async_tracer.scope_manager._set_task_scope(scope, task=task)
+                setattr(task, ACTIVE_ATTR, scope)
 
             return task
 

instana/singletons.py

@@ -94,13 +94,11 @@ def set_agent(new_agent):
 # this package.
 tracer = InstanaTracer(recorder=span_recorder)
 
-if sys.version_info >= (3, 4):
-    try:
-        from opentracing.scope_managers.asyncio import AsyncioScopeManager
-
-        async_tracer = InstanaTracer(scope_manager=AsyncioScopeManager(), recorder=span_recorder)
-    except Exception:
-        logger.debug("Error setting up async_tracer:", exc_info=True)
+try:
+    from opentracing.scope_managers.contextvars import ContextVarsScopeManager
+    async_tracer = InstanaTracer(scope_manager=ContextVarsScopeManager(), recorder=span_recorder)
+except Exception:
+    logger.debug("Error setting up async_tracer:", exc_info=True)
 
 # Mock the tornado tracer until tornado is detected and instrumented first
 tornado_tracer = tracer