Mitigate CPU spikes when sending lots of events with lots of data (#2449)

Increasing the HTTP pool size to better handle the requests. 

This does not fix all CPU spikes, but instead of spikes happening every 1 in 3-4 times it only happens 1 in 7-8 times with my test script.

Author: antonpirker

sentry_sdk/consts.py

@@ -43,6 +43,7 @@
             "profiler_mode": Optional[ProfilerMode],
             "otel_powered_performance": Optional[bool],
             "transport_zlib_compression_level": Optional[int],
+            "transport_num_pools": Optional[int],
             "enable_metrics": Optional[bool],
             "before_emit_metric": Optional[Callable[[str, MetricTags], bool]],
         },

sentry_sdk/transport.py

@@ -157,6 +157,14 @@ def __init__(
         )  # type: DefaultDict[Tuple[str, str], int]
         self._last_client_report_sent = time.time()
 
+        compresslevel = options.get("_experiments", {}).get(
+            "transport_zlib_compression_level"
+        )
+        self._compresslevel = 9 if compresslevel is None else int(compresslevel)
+
+        num_pools = options.get("_experiments", {}).get("transport_num_pools")
+        self._num_pools = 2 if num_pools is None else int(num_pools)
+
         self._pool = self._make_pool(
             self.parsed_dsn,
             http_proxy=options["http_proxy"],
@@ -165,11 +173,6 @@ def __init__(
             proxy_headers=options["proxy_headers"],
         )
 
-        compresslevel = options.get("_experiments", {}).get(
-            "transport_zlib_compression_level"
-        )
-        self._compresslevel = 9 if compresslevel is None else int(compresslevel)
-
         from sentry_sdk import Hub
 
         self.hub_cls = Hub
@@ -439,7 +442,7 @@ def _send_envelope(
     def _get_pool_options(self, ca_certs):
         # type: (Optional[Any]) -> Dict[str, Any]
         return {
-            "num_pools": 2,
+            "num_pools": self._num_pools,
             "cert_reqs": "CERT_REQUIRED",
             "ca_certs": ca_certs or certifi.where(),
         }

tests/test_transport.py

@@ -132,6 +132,25 @@ def test_transport_works(
     assert any("Sending event" in record.msg for record in caplog.records) == debug
 
 
+@pytest.mark.parametrize(
+    "num_pools,expected_num_pools",
+    (
+        (None, 2),
+        (2, 2),
+        (10, 10),
+    ),
+)
+def test_transport_num_pools(make_client, num_pools, expected_num_pools):
+    _experiments = {}
+    if num_pools is not None:
+        _experiments["transport_num_pools"] = num_pools
+
+    client = make_client(_experiments=_experiments)
+
+    options = client.transport._get_pool_options([])
+    assert options["num_pools"] == expected_num_pools
+
+
 def test_transport_infinite_loop(capturing_server, request, make_client):
     client = make_client(
         debug=True,