Add distributed_tracing.sampler.*root.* config support (#1586)

* Add root config

* [MegaLinter] Apply linters fixes

---------

Co-authored-by: hmstepanek <30059933+hmstepanek@users.noreply.github.com>

Author: hmstepanek

newrelic/api/transaction.py

@@ -1022,12 +1022,25 @@ def sampling_algo_compute_sampled_and_priority(self, priority, sampled, sampler_
         return priority, sampled
 
     def _compute_sampled_and_priority(
-        self, priority, sampled, full_granularity, remote_parent_sampled_setting, remote_parent_not_sampled_setting
+        self,
+        priority,
+        sampled,
+        full_granularity,
+        root_setting,
+        remote_parent_sampled_setting,
+        remote_parent_not_sampled_setting,
     ):
         if self._remote_parent_sampled is None:
             section = 0
-            config = "default"  # Use sampling algo.
-            _logger.debug("Sampling decision made based on no remote parent sampling decision present.")
+            setting_path = (
+                f"distributed_tracing.sampler.{'full_granularity' if full_granularity else 'partial_granularity'}.root"
+            )
+            config = root_setting
+            _logger.debug(
+                "Sampling decision made based on no remote parent sampling decision present and %s=%s.",
+                setting_path,
+                config,
+            )
         elif self._remote_parent_sampled:
             section = 1
             setting_path = f"distributed_tracing.sampler.{'full_granularity' if full_granularity else 'partial_granularity'}.remote_parent_sampled"
@@ -1084,6 +1097,7 @@ def _make_sampling_decision(self):
                 priority,
                 sampled,
                 full_granularity=True,
+                root_setting=self.settings.distributed_tracing.sampler.full_granularity._root,
                 remote_parent_sampled_setting=self.settings.distributed_tracing.sampler.full_granularity._remote_parent_sampled,
                 remote_parent_not_sampled_setting=self.settings.distributed_tracing.sampler.full_granularity._remote_parent_not_sampled,
             )
@@ -1101,6 +1115,7 @@ def _make_sampling_decision(self):
                 priority,
                 sampled,
                 full_granularity=False,
+                root_setting=self.settings.distributed_tracing.sampler.partial_granularity._root,
                 remote_parent_sampled_setting=self.settings.distributed_tracing.sampler.partial_granularity._remote_parent_sampled,
                 remote_parent_not_sampled_setting=self.settings.distributed_tracing.sampler.partial_granularity._remote_parent_not_sampled,
             )

newrelic/config.py

@@ -534,6 +534,10 @@ def _process_configuration(section):
     _process_setting(section, "distributed_tracing.enabled", "getboolean", None)
     _process_setting(section, "distributed_tracing.exclude_newrelic_header", "getboolean", None)
     _process_setting(section, "distributed_tracing.sampler.adaptive_sampling_target", "getint", None)
+    _process_dt_hidden_setting(section, "distributed_tracing.sampler.full_granularity.root", "get")
+    _process_dt_sampler_setting(
+        section, "distributed_tracing.sampler.full_granularity.root.adaptive.sampling_target", "getint"
+    )
     _process_dt_setting(
         section,
         "distributed_tracing.sampler.full_granularity.remote_parent_sampled",
@@ -557,6 +561,10 @@ def _process_configuration(section):
     _process_setting(section, "distributed_tracing.sampler.full_granularity.enabled", "getboolean", None)
     _process_setting(section, "distributed_tracing.sampler.partial_granularity.enabled", "getboolean", None)
     _process_setting(section, "distributed_tracing.sampler.partial_granularity.type", "get", None)
+    _process_dt_hidden_setting(section, "distributed_tracing.sampler.partial_granularity.root", "get")
+    _process_dt_sampler_setting(
+        section, "distributed_tracing.sampler.partial_granularity.root.adaptive.sampling_target", "getint"
+    )
     _process_dt_hidden_setting(section, "distributed_tracing.sampler.partial_granularity.remote_parent_sampled", "get")
     _process_dt_sampler_setting(
         section,

newrelic/core/config.py

@@ -338,10 +338,19 @@ class DistributedTracingSamplerSettings(Settings):
 
 
 class DistributedTracingSamplerFullGranularitySettings(Settings):
+    _root = "default"
     _remote_parent_sampled = "default"
     _remote_parent_not_sampled = "default"
 
 
+class DistributedTracingSamplerFullGranularityRootSettings:
+    pass
+
+
+class DistributedTracingSamplerFullGranularityRootAdaptiveSettings:
+    pass
+
+
 class DistributedTracingSamplerFullGranularityRemoteParentSampledSettings:
     pass
 
@@ -359,10 +368,19 @@ class DistributedTracingSamplerFullGranularityRemoteParentNotSampledAdaptiveSett
 
 
 class DistributedTracingSamplerPartialGranularitySettings(Settings):
+    _root = "default"
     _remote_parent_sampled = "default"
     _remote_parent_not_sampled = "default"
 
 
+class DistributedTracingSamplerPartialGranularityRootSettings:
+    pass
+
+
+class DistributedTracingSamplerPartialGranularityRootAdaptiveSettings:
+    pass
+
+
 class DistributedTracingSamplerPartialGranularityRemoteParentSampledSettings:
     pass
 
@@ -550,6 +568,10 @@ class EventHarvestConfigHarvestLimitSettings(Settings):
 _settings.distributed_tracing = DistributedTracingSettings()
 _settings.distributed_tracing.sampler = DistributedTracingSamplerSettings()
 _settings.distributed_tracing.sampler.full_granularity = DistributedTracingSamplerFullGranularitySettings()
+_settings.distributed_tracing.sampler.full_granularity.root = DistributedTracingSamplerFullGranularityRootSettings()
+_settings.distributed_tracing.sampler.full_granularity.root.adaptive = (
+    DistributedTracingSamplerFullGranularityRootAdaptiveSettings()
+)
 _settings.distributed_tracing.sampler.full_granularity.remote_parent_sampled = (
     DistributedTracingSamplerFullGranularityRemoteParentSampledSettings()
 )
@@ -563,6 +585,12 @@ class EventHarvestConfigHarvestLimitSettings(Settings):
     DistributedTracingSamplerFullGranularityRemoteParentNotSampledAdaptiveSettings()
 )
 _settings.distributed_tracing.sampler.partial_granularity = DistributedTracingSamplerPartialGranularitySettings()
+_settings.distributed_tracing.sampler.partial_granularity.root = (
+    DistributedTracingSamplerPartialGranularityRootSettings()
+)
+_settings.distributed_tracing.sampler.partial_granularity.root.adaptive = (
+    DistributedTracingSamplerPartialGranularityRootAdaptiveSettings()
+)
 _settings.distributed_tracing.sampler.partial_granularity.remote_parent_sampled = (
     DistributedTracingSamplerPartialGranularityRemoteParentSampledSettings()
 )
@@ -918,6 +946,14 @@ def default_otlp_host(host):
 _settings.distributed_tracing.sampler.full_granularity.enabled = _environ_as_bool(
     "NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_FULL_GRANULARITY_ENABLED", default=True
 )
+_settings.distributed_tracing.sampler.full_granularity._root = (
+    "adaptive"
+    if os.environ.get("NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_FULL_GRANULARITY_ROOT_ADAPTIVE_SAMPLING_TARGET", None)
+    else None
+) or os.environ.get("NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_FULL_GRANULARITY_ROOT", "default")
+_settings.distributed_tracing.sampler.full_granularity.root.adaptive.sampling_target = _environ_as_int(
+    "NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_FULL_GRANULARITY_ROOT_ADAPTIVE_SAMPLING_TARGET", None
+)
 _settings.distributed_tracing.sampler.full_granularity._remote_parent_sampled = (
     (
         "adaptive"
@@ -957,6 +993,14 @@ def default_otlp_host(host):
 _settings.distributed_tracing.sampler.partial_granularity.type = os.environ.get(
     "NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_PARTIAL_GRANULARITY_TYPE", "essential"
 )
+_settings.distributed_tracing.sampler.partial_granularity._root = (
+    "adaptive"
+    if os.environ.get("NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_PARTIAL_GRANULARITY_ROOT_ADAPTIVE_SAMPLING_TARGET", None)
+    else None
+) or os.environ.get("NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_PARTIAL_GRANULARITY_ROOT", "default")
+_settings.distributed_tracing.sampler.partial_granularity.root.adaptive.sampling_target = _environ_as_int(
+    "NEW_RELIC_DISTRIBUTED_TRACING_SAMPLER_PARTIAL_GRANULARITY_ROOT_ADAPTIVE_SAMPLING_TARGET", None
+)
 _settings.distributed_tracing.sampler.partial_granularity._remote_parent_sampled = (
     "adaptive"
     if os.environ.get(

newrelic/core/samplers/sampler_proxy.py

@@ -23,6 +23,11 @@ def __init__(self, settings):
         adaptive_sampler = AdaptiveSampler(settings.sampling_target, sampling_target_period)
         self._samplers = {"global": adaptive_sampler}
         # Add adaptive sampler instances for each config section if configured.
+        self.add_adaptive_sampler(
+            (True, 0),
+            settings.distributed_tracing.sampler.full_granularity.root.adaptive.sampling_target,
+            sampling_target_period,
+        )
         self.add_adaptive_sampler(
             (True, 1),
             settings.distributed_tracing.sampler.full_granularity.remote_parent_sampled.adaptive.sampling_target,
@@ -33,6 +38,11 @@ def __init__(self, settings):
             settings.distributed_tracing.sampler.full_granularity.remote_parent_not_sampled.adaptive.sampling_target,
             sampling_target_period,
         )
+        self.add_adaptive_sampler(
+            (False, 0),
+            settings.distributed_tracing.sampler.partial_granularity.root.adaptive.sampling_target,
+            sampling_target_period,
+        )
         self.add_adaptive_sampler(
             (False, 1),
             settings.distributed_tracing.sampler.partial_granularity.remote_parent_sampled.adaptive.sampling_target,