feat(profiling): add DD_PROFILING_HEAP_ENABLED env var to enable heap profiler (#2580)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Kyle Verhoog <[email protected]>
Co-authored-by: Gabriele N. Tornetta <[email protected]>

Author: 4 people

ddtrace/profiling/collector/memalloc.py

@@ -48,9 +48,6 @@ class MemoryHeapSampleEvent(event.StackBasedEvent):
     """The sampling size."""
 
 
-_ENABLED = False
-
-
 def _get_default_heap_sample_size(
     default_heap_sample_size=512 * 1024,  # type: int
 ):
@@ -59,7 +56,7 @@ def _get_default_heap_sample_size(
     if heap_sample_size is not None:
         return int(heap_sample_size)
 
-    if not _ENABLED:
+    if not formats.asbool(os.environ.get("DD_PROFILING_HEAP_ENABLED", "0")):
         return 0
 
     try:

docs/configuration.rst

@@ -121,6 +121,10 @@ below:
      - Integer
      - 64
      - The maximum number of frames to capture in stack execution tracing.
+   * - ``DD_PROFILING_HEAP_ENABLED``
+     - Boolean
+     - False
+     - Whether to enable the heap memory profiler.
    * - ``DD_PROFILING_CAPTURE_PCT``
      - Float
      - 2

releasenotes/notes/profiling-heap-profiler-enabling-186ae7679b84d39a.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    The Python heap profiler can now be enabled by setting the
+    ``DD_PROFILING_HEAP_ENABLED`` environment variable to ``1``.

tests/profiling/collector/test_memalloc.py

@@ -333,13 +333,9 @@ def test_memalloc_speed(benchmark, heap_sample_size):
         (False, (lambda v: v == 0, lambda v: v == 0, lambda v: v == 0, lambda v: v == 0)),
     ),
 )
-def test_memalloc_sample_size(enabled, predicates):
-    restore = memalloc._ENABLED
-    memalloc._ENABLED = enabled
-    try:
-        assert predicates[0](memalloc._get_default_heap_sample_size())
-        assert predicates[1](memalloc._get_default_heap_sample_size(1))
-        assert predicates[2](memalloc._get_default_heap_sample_size(512))
-        assert predicates[3](memalloc._get_default_heap_sample_size(512 * 1024 * 1024))
-    finally:
-        memalloc._ENABLED = restore
+def test_memalloc_sample_size(enabled, predicates, monkeypatch):
+    monkeypatch.setenv("DD_PROFILING_HEAP_ENABLED", str(enabled))
+    assert predicates[0](memalloc._get_default_heap_sample_size())
+    assert predicates[1](memalloc._get_default_heap_sample_size(1))
+    assert predicates[2](memalloc._get_default_heap_sample_size(512))
+    assert predicates[3](memalloc._get_default_heap_sample_size(512 * 1024 * 1024))