ref(profiling): Do not send single sample profiles

sentry_sdk/profiler.py

@@ -135,14 +135,18 @@ def is_gevent():
 
 _scheduler = None  # type: Optional[Scheduler]
 
+# The default sampling frequency to use. This is set at 101 in order to
+# mitigate the effects of lockstep sampling.
+DEFAULT_SAMPLING_FREQUENCY = 101
+
+
+# The minimum number of unique samples that must exist in a profile to be
+# considered valid.
+PROFILE_MINIMUM_SAMPLES = 2
+
 
 def setup_profiler(options):
     # type: (Dict[str, Any]) -> bool
-    """
-    `buffer_secs` determines the max time a sample will be buffered for
-    `frequency` determines the number of samples to take per second (Hz)
-    """
-
     global _scheduler
 
     if _scheduler is not None:
@@ -153,7 +157,7 @@ def setup_profiler(options):
         logger.warn("profiling is only supported on Python >= 3.3")
         return False
 
-    frequency = 101
+    frequency = DEFAULT_SAMPLING_FREQUENCY
 
     if is_gevent():
         # If gevent has patched the threading modules then we cannot rely on
@@ -429,6 +433,8 @@ def __init__(
         self.stacks = []  # type: List[ProcessedStack]
         self.samples = []  # type: List[ProcessedSample]
 
+        self.unique_samples = 0
+
         transaction._profile = self
 
     def update_active_thread_id(self):
@@ -540,6 +546,8 @@ def write(self, ts, sample):
             self.stop()
             return
 
+        self.unique_samples += 1
+
         elapsed_since_start_ns = str(offset)
 
         for tid, (stack_id, stack) in sample:
@@ -641,6 +649,10 @@ def to_json(self, event_opt, options):
             ],
         }
 
+    def valid(self):
+        # type: () -> bool
+        return self.sampled is not None and self.sampled and self.unique_samples >= PROFILE_MINIMUM_SAMPLES
+
 
 class Scheduler(object):
     mode = "unknown"

sentry_sdk/tracing.py

@@ -716,7 +716,7 @@ def finish(self, hub=None, end_timestamp=None):
             "spans": finished_spans,
         }  # type: Event
 
-        if self._profile is not None and self._profile.sampled:
+        if self._profile is not None and self._profile.valid():
             event["profile"] = self._profile
             contexts.update({"profile": self._profile.get_profile_context()})
             self._profile = None

tests/integrations/django/asgi/test_asgi.py

@@ -1,4 +1,5 @@
 import json
+import mock
 
 import django
 import pytest
@@ -78,6 +79,7 @@ async def test_async_views(sentry_init, capture_events, application):
 @pytest.mark.skipif(
     django.VERSION < (3, 1), reason="async views have been introduced in Django 3.1"
 )
+@mock.patch("sentry_sdk.profiler.PROFILE_MINIMUM_SAMPLES", 0)
 async def test_active_thread_id(
     sentry_init, capture_envelopes, teardown_profiling, endpoint, application
 ):

tests/integrations/fastapi/test_fastapi.py

@@ -1,4 +1,5 @@
 import json
+import mock
 import threading
 
 import pytest
@@ -155,6 +156,7 @@ def test_legacy_setup(
 
 
 @pytest.mark.parametrize("endpoint", ["/sync/thread_ids", "/async/thread_ids"])
+@mock.patch("sentry_sdk.profiler.PROFILE_MINIMUM_SAMPLES", 0)
 def test_active_thread_id(sentry_init, capture_envelopes, teardown_profiling, endpoint):
     sentry_init(
         traces_sample_rate=1.0,

tests/integrations/starlette/test_starlette.py

@@ -2,6 +2,7 @@
 import base64
 import functools
 import json
+import mock
 import os
 import threading
 
@@ -846,6 +847,7 @@ def test_legacy_setup(
 
 
 @pytest.mark.parametrize("endpoint", ["/sync/thread_ids", "/async/thread_ids"])
+@mock.patch("sentry_sdk.profiler.PROFILE_MINIMUM_SAMPLES", 0)
 def test_active_thread_id(sentry_init, capture_envelopes, teardown_profiling, endpoint):
     sentry_init(
         traces_sample_rate=1.0,

tests/integrations/wsgi/test_wsgi.py

@@ -1,3 +1,4 @@
+import mock
 import sys
 
 from werkzeug.test import Client
@@ -287,6 +288,7 @@ def sample_app(environ, start_response):
 @pytest.mark.skipif(
     sys.version_info < (3, 3), reason="Profiling is only supported in Python >= 3.3"
 )
+@mock.patch("sentry_sdk.profiler.PROFILE_MINIMUM_SAMPLES", 0)
 def test_profile_sent(
     sentry_init,
     capture_envelopes,

tests/test_profiler.py

@@ -88,6 +88,7 @@ def test_profiler_setup_twice(teardown_profiling):
         pytest.param(None, 0, id="profiler not enabled"),
     ],
 )
+@mock.patch("sentry_sdk.profiler.PROFILE_MINIMUM_SAMPLES", 0)
 def test_profiled_transaction(
     sentry_init,
     capture_envelopes,
@@ -115,6 +116,7 @@ def test_profiled_transaction(
     assert len(items["profile"]) == profile_count
 
 
+@mock.patch("sentry_sdk.profiler.PROFILE_MINIMUM_SAMPLES", 0)
 def test_profile_context(
     sentry_init,
     capture_envelopes,
@@ -145,6 +147,32 @@ def test_profile_context(
     }
 
 
+def test_minimum_unique_samples_required(
+    sentry_init,
+    capture_envelopes,
+    teardown_profiling,
+):
+    sentry_init(
+        traces_sample_rate=1.0,
+        _experiments={"profiles_sample_rate": 1.0},
+    )
+
+    envelopes = capture_envelopes()
+
+    with start_transaction(name="profiling"):
+        pass
+
+    items = defaultdict(list)
+    for envelope in envelopes:
+        for item in envelope.items:
+            items[item.type].append(item)
+
+    assert len(items["transaction"]) == 1
+    # because we dont leave any time for the profiler to
+    # take any samples, it should be not be sent
+    assert len(items["profile"]) == 0
+
+
 def get_frame(depth=1):
     """
     This function is not exactly true to its name. Depending on
@@ -478,7 +506,7 @@ def test_thread_scheduler_single_background_thread(scheduler_class):
         pytest.param(GeventScheduler, marks=requires_gevent, id="gevent scheduler"),
     ],
 )
-@mock.patch("sentry_sdk.profiler.MAX_PROFILE_DURATION_NS", int(1))
+@mock.patch("sentry_sdk.profiler.MAX_PROFILE_DURATION_NS", 1)
 def test_max_profile_duration_reached(scheduler_class):
     sample = [
         (
@@ -792,7 +820,7 @@ def test_max_profile_duration_reached(scheduler_class):
         pytest.param(GeventScheduler, marks=requires_gevent, id="gevent scheduler"),
     ],
 )
-@mock.patch("sentry_sdk.profiler.MAX_PROFILE_DURATION_NS", int(5))
+@mock.patch("sentry_sdk.profiler.MAX_PROFILE_DURATION_NS", 5)
 def test_profile_processing(
     DictionaryContaining,  # noqa: N803
     scheduler_class,