collect threads count in opentelemetry-instrumentation-system-metrics

Author: yulin-li

instrumentation/opentelemetry-instrumentation-system-metrics/src/opentelemetry/instrumentation/system_metrics/__init__.py

@@ -42,7 +42,8 @@
         "system.network.connections": ["family", "type"],
         "runtime.memory": ["rss", "vms"],
         "runtime.cpu.time": ["user", "system"],
-        "runtime.gc_count": None
+        "runtime.gc_count": None,
+        "runtime.threading.active_count": None
     }
 
 Usage
@@ -80,6 +81,7 @@
 
 import gc
 import os
+import threading
 from platform import python_implementation
 from typing import Collection, Dict, Iterable, List, Optional
 
@@ -118,6 +120,7 @@
     "runtime.memory": ["rss", "vms"],
     "runtime.cpu.time": ["user", "system"],
     "runtime.gc_count": None,
+    "runtime.threading.active_count": None,
 }
 
 
@@ -168,6 +171,7 @@ def __init__(
         self._runtime_memory_labels = self._labels.copy()
         self._runtime_cpu_time_labels = self._labels.copy()
         self._runtime_gc_count_labels = self._labels.copy()
+        self._runtime_threading_active_count_labels = self._labels.copy()
 
     def instrumentation_dependencies(self) -> Collection[str]:
         return _instruments
@@ -415,6 +419,14 @@ def _instrument(self, **kwargs):
                 unit="bytes",
             )
 
+        if "runtime.threading.active_count" in self._config:
+            self._meter.create_observable_gauge(
+                name=f"runtime.{self._python_implementation}.threading.active_count",
+                callbacks=[self._get_runtime_threading_active_count],
+                description=f"Runtime {self._python_implementation} active threads count",
+                unit="threads",
+            )
+
     def _uninstrument(self, **__):
         pass
 
@@ -747,3 +759,11 @@ def _get_runtime_gc_count(
         for index, count in enumerate(gc.get_count()):
             self._runtime_gc_count_labels["count"] = str(index)
             yield Observation(count, self._runtime_gc_count_labels.copy())
+
+    def _get_runtime_threading_active_count(
+        self, options: CallbackOptions
+    ) -> Iterable[Observation]:
+        """Observer callback for threading active count"""
+        yield Observation(
+            threading.active_count(), self._runtime_threading_active_count_labels
+        )