feat: move away from a ParentBased sampling approach.

src/honeycomb/opentelemetry/sampler.py

@@ -1,9 +1,9 @@
 from logging import getLogger
 
 from opentelemetry.sdk.trace.sampling import (
-    DEFAULT_OFF,
-    DEFAULT_ON,
-    ParentBasedTraceIdRatio,
+    ALWAYS_OFF,
+    ALWAYS_ON,
+    TraceIdRatioBased,
     Sampler,
     SamplingResult
 )
@@ -24,11 +24,11 @@ def configure_sampler(
     """Configures and returns an OpenTelemetry Sampler that is
     configured based on the sample_rate determined in HoneycombOptions.
     The configuration initializes a DeterministicSampler with
-    an inner sampler of either DefaultOn (1), Default Off (0),
+    an inner sampler of either AlwaysOn (1), AlwaysOff (0),
     or a TraceIdRatio as 1/N.
 
-    Each of these samplers is ParentBased, meaning it respects
-    its parent span's sampling decision.
+    These samplers do not take into account the parent span's
+    sampling decision.
 
     Args:
         options (HoneycombOptions): the HoneycombOptins containing
@@ -42,34 +42,32 @@ def configure_sampler(
 
 class DeterministicSampler(Sampler):
     """Implementation of :class:`Sampler` that uses an inner sampler
-    of either DefaultOn (1), Default Off (0), or a TraceIdRatio as 1/N
+    of either AlwaysOn (1), AlwaysOff (0), or a TraceIdRatio as 1/N
     to determine a SamplingResult and SamplingDecision for a given span
     in a trace. We append a SampleRate attribute to the span with the
     given sample rate.
 
-    Note: Each of these samplers is ParentBased, meaning it respects
-    its parent span's sampling decision.
+    Note: These samplers do not take into account the parent span's
+    sampling decision.
     """
 
     def __init__(self, rate: int):
         self.rate = rate
 
         if self.rate <= 0:
-            # Sampler that respects its parent span's sampling decision,
-            # but otherwise never samples. If it's negative, we assume
-            # a sample rate of 0
-            self._sampler = DEFAULT_OFF
+            # Sampler that never samples spans, regardless of the
+            # parent span's sampling decision
+            self._sampler = ALWAYS_OFF
 
         elif self.rate == 1:
-            # Sampler that respects its parent span's sampling decision,
-            # but otherwise always samples.
-            self._sampler = DEFAULT_ON
+            # Sampler that always samples spans, regardless of the
+            # parent span's sampling decision
+            self._sampler = ALWAYS_ON
 
         else:
-            # Sampler that respects its parent span's sampling decision,
-            # but otherwise samples probabalistically based on `rate`.
+            # Sampler that samples probabalistically based on rate..
             ratio = 1.0 / self.rate
-            self._sampler = ParentBasedTraceIdRatio(ratio)
+            self._sampler = TraceIdRatioBased(ratio)
 
     # pylint: disable=too-many-arguments
     def should_sample(

tests/test_sampler.py

@@ -1,9 +1,9 @@
 from opentelemetry import context
 from opentelemetry.trace import SpanKind
 from opentelemetry.sdk.trace.sampling import (
-    DEFAULT_OFF,
-    DEFAULT_ON,
-    ParentBasedTraceIdRatio,
+    ALWAYS_OFF,
+    ALWAYS_ON,
+    TraceIdRatioBased,
     Decision
 )
 
@@ -29,13 +29,13 @@ def get_sampling_result(test_sampler):
     )
 
 
-def test_sample_with_undefined_rate_defaults_to_DEFAULT_ON_and_recorded():
+def test_sample_with_undefined_rate_defaults_to_ALWAYS_ON_and_recorded():
     undefined_rate_sampler = configure_sampler()
     # test the `DEFAULT_SAMPLE_RATE` is applied (i.e. 1)
     assert undefined_rate_sampler.rate == DEFAULT_SAMPLE_RATE
     # test the inner DeterministicSampler choice
     inner_sampler = undefined_rate_sampler._sampler
-    assert inner_sampler == DEFAULT_ON
+    assert inner_sampler == ALWAYS_ON
     assert isinstance(undefined_rate_sampler, DeterministicSampler)
     # test the SamplingResult is as expected
     sampling_result = get_sampling_result(undefined_rate_sampler)
@@ -46,46 +46,46 @@ def test_sample_with_undefined_rate_defaults_to_DEFAULT_ON_and_recorded():
     }
 
 
-def test_sampler_with_rate_of_one_is_DEFAULT_ON_and_recorded():
+def test_sampler_with_rate_of_one_is_ALWAYS_ON_and_recorded():
     sample_rate_one = HoneycombOptions(sample_rate=1)
-    default_on_sampler = configure_sampler(sample_rate_one)
+    always_on_sampler = configure_sampler(sample_rate_one)
     # test the inner DeterministicSampler choice and rate
-    inner_sampler = default_on_sampler._sampler
-    assert inner_sampler == DEFAULT_ON
-    assert isinstance(default_on_sampler, DeterministicSampler)
-    assert default_on_sampler.rate == 1
+    inner_sampler = always_on_sampler._sampler
+    assert inner_sampler == ALWAYS_ON
+    assert isinstance(always_on_sampler, DeterministicSampler)
+    assert always_on_sampler.rate == 1
     # test the SamplingResult is as expected
-    sampling_result = get_sampling_result(default_on_sampler)
+    sampling_result = get_sampling_result(always_on_sampler)
     assert sampling_result.decision.is_sampled()
     assert sampling_result.attributes == {
         'existing_attr': 'is intact',
         'SampleRate': 1
     }
 
 
-def test_sampler_with_rate_of_zero_is_DEFAULT_OFF_and_DROP():
+def test_sampler_with_rate_of_zero_is_ALWAYS_OFF_and_DROP():
     sample_rate_zero = HoneycombOptions(sample_rate=0)
-    default_off_sampler = configure_sampler(sample_rate_zero)
+    always_off_sampler = configure_sampler(sample_rate_zero)
     # test the inner DeterministicSampler choice and rate
-    inner_sampler = default_off_sampler._sampler
-    assert inner_sampler == DEFAULT_OFF
-    assert isinstance(default_off_sampler, DeterministicSampler)
-    assert default_off_sampler.rate == 0
+    inner_sampler = always_off_sampler._sampler
+    assert inner_sampler == ALWAYS_OFF
+    assert isinstance(always_off_sampler, DeterministicSampler)
+    assert always_off_sampler.rate == 0
     # test the SamplingResult is as expected
-    sampling_result = get_sampling_result(default_off_sampler)
+    sampling_result = get_sampling_result(always_off_sampler)
     assert sampling_result.decision.is_sampled() is False
     assert sampling_result.decision == Decision.DROP
     assert sampling_result.attributes == {}
 
 
-def test_sampler_with_rate_of_ten_configures_ParentBasedTraceIdRatio():
+def test_sampler_with_rate_of_ten_configures_TraceIdRatioBased():
     sample_rate_ten = HoneycombOptions(sample_rate=10)
     trace_id_ratio_sampler = configure_sampler(sample_rate_ten)
     # test the inner DeterministicSampler choice and rate
     inner_sampler = trace_id_ratio_sampler._sampler
     assert isinstance(
         inner_sampler,
-        ParentBasedTraceIdRatio
+        TraceIdRatioBased
     )
     assert isinstance(
         trace_id_ratio_sampler,