feat(profiling): disable trace tracking in tracer by default (#1488) (#1502)

This disables the tracer usage by default in the profiler.

Co-authored-by: Julien Danjou <[email protected]>

Author: Kyle-Verhoog

ddtrace/profiling/collector/stack.pyx

@@ -262,7 +262,8 @@ cdef stack_collect(ignore_profiler, thread_time, max_nframes, interval, wall_tim
 
     running_thread_ids = {t[0] for t in running_threads}
 
-    thread_span_links.clear_threads(running_thread_ids)
+    if thread_span_links:
+        thread_span_links.clear_threads(running_thread_ids)
 
     if ignore_profiler:
         running_thread_ids -= _periodic.PERIODIC_THREAD_IDS
@@ -273,7 +274,10 @@ cdef stack_collect(ignore_profiler, thread_time, max_nframes, interval, wall_tim
     for tid, frame in running_threads:
         if ignore_profiler and tid in _periodic.PERIODIC_THREAD_IDS:
             continue
-        spans = thread_span_links.get_active_leaf_spans_from_thread_id(tid)
+        if thread_span_links:
+            spans = thread_span_links.get_active_leaf_spans_from_thread_id(tid)
+        else:
+            spans = set()
         frames, nframes = _traceback.pyframe_to_frames(frame, max_nframes)
         stack_events.append(
             StackSampleEvent(
@@ -376,7 +380,7 @@ class StackCollector(collector.PeriodicCollector):
     tracer = attr.ib(default=None)
     _thread_time = attr.ib(init=False, repr=False)
     _last_wall_time = attr.ib(init=False, repr=False)
-    _thread_span_links = attr.ib(factory=_ThreadSpanLinks, init=False, repr=False)
+    _thread_span_links = attr.ib(default=None, init=False, repr=False)
 
     @max_time_usage_pct.validator
     def _check_max_time_usage(self, attribute, value):
@@ -387,6 +391,7 @@ class StackCollector(collector.PeriodicCollector):
         self._thread_time = ThreadTime()
         self._last_wall_time = compat.monotonic_ns()
         if self.tracer is not None:
+            self._thread_span_links = _ThreadSpanLinks()
             self.tracer.on_start_span(self._thread_span_links.link_span)
         super(StackCollector, self).start()
 

ddtrace/profiling/profiler.py

@@ -2,7 +2,6 @@
 import logging
 import os
 
-import ddtrace
 from ddtrace.profiling import recorder
 from ddtrace.profiling import scheduler
 from ddtrace.vendor import attr
@@ -32,16 +31,6 @@ def _build_default_exporters():
     return exporters
 
 
-def _build_default_collectors():
-    r = recorder.Recorder()
-    return [
-        stack.StackCollector(r, tracer=ddtrace.tracer),
-        memory.MemoryCollector(r),
-        exceptions.UncaughtExceptionCollector(r),
-        threading.LockCollector(r),
-    ]
-
-
 # This ought to use `enum.Enum`, but since it's not available in Python 2, we just use a dumb class.
 @attr.s(repr=False)
 class ProfilerStatus(object):
@@ -69,12 +58,26 @@ class Profiler(object):
 
     """
 
-    collectors = attr.ib(factory=_build_default_collectors)
+    collectors = attr.ib(default=None)
     exporters = attr.ib(factory=_build_default_exporters)
     schedulers = attr.ib(init=False, factory=list)
     status = attr.ib(init=False, type=ProfilerStatus, default=ProfilerStatus.STOPPED)
+    tracer = attr.ib(default=None)
+
+    @staticmethod
+    def _build_default_collectors(tracer):
+        r = recorder.Recorder()
+        return [
+            stack.StackCollector(r, tracer=tracer),
+            memory.MemoryCollector(r),
+            exceptions.UncaughtExceptionCollector(r),
+            threading.LockCollector(r),
+        ]
 
     def __attrs_post_init__(self):
+        if self.collectors is None:
+            self.collectors = self._build_default_collectors(self.tracer)
+
         if self.exporters:
             for rec in self.recorders:
                 self.schedulers.append(scheduler.Scheduler(recorder=rec, exporters=self.exporters))

tests/profiling/test_profiler.py

@@ -1,4 +1,8 @@
+import pytest
+
+import ddtrace
 from ddtrace.profiling import profiler
+from ddtrace.profiling.collector import stack
 
 
 def test_status():
@@ -16,3 +20,15 @@ def test_restart():
     p.stop()
     p.start()
     p.stop()
+
+
+def test_tracer_api(monkeypatch):
+    monkeypatch.setenv("DD_API_KEY", "foobar")
+    prof = profiler.Profiler(tracer=ddtrace.tracer)
+    assert prof.tracer == ddtrace.tracer
+    for collector in prof.collectors:
+        if isinstance(collector, stack.StackCollector):
+            assert collector.tracer == ddtrace.tracer
+            break
+    else:
+        pytest.fail("Unable to find stack collector")