Enable only on Linux platforms, and add config flag

benoitc · Aug 14, 2024 · c35802f · c35802f
1 parent aa73f3c
commit c35802f
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Showing 4 changed files with 53 additions and 23 deletions.
diff --git a/docs/source/settings.rst b/docs/source/settings.rst
@@ -461,6 +461,19 @@ if not provided).
 
 .. versionadded:: 19.2
 
+.. _enable-backlog-metric:
+
+``enable_backlog_metric``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+**Command line:** ``--enable-backlog-metric``
+
+**Default:** ``False``
+
+Enable socket backlog metric (only supported on Linux).
+
+.. versionadded:: 23.1
+
 Process Naming
 --------------
 

diff --git a/gunicorn/arbiter.py b/gunicorn/arbiter.py
@@ -583,16 +583,15 @@ def manage_workers(self):
                                   "value": active_worker_count,
                                   "mtype": "gauge"})
 
-        backlog = sum(
-            sock.get_backlog() or 0
-            for sock in self.LISTENERS
-        )
-
-        if backlog:
-            self.log.debug("socket backlog: {0}".format(backlog),
-                           extra={"metric": "gunicorn.backlog",
-                                  "value": backlog,
-                                  "mtype": "histogram"})
+        if self.cfg.enable_backlog_metric:
+            backlog = sum(sock.get_backlog() or 0
+                          for sock in self.LISTENERS)
+
+            if backlog:
+                self.log.debug("socket backlog: {0}".format(backlog),
+                               extra={"metric": "gunicorn.backlog",
+                                      "value": backlog,
+                                      "mtype": "histogram"})
 
     def spawn_worker(self):
         self.worker_age += 1

diff --git a/gunicorn/config.py b/gunicorn/config.py
@@ -1693,6 +1693,21 @@ class StatsdPrefix(Setting):
     """
 
 
+class BacklogMetric(Setting):
+    name = "enable_backlog_metric"
+    section = "Logging"
+    cli = ["--enable-backlog-metric"]
+    meta = "BACKLOG_METRIC"
+    validator = validate_bool
+    default = False
+    action = "store_true"
+    desc = """\
+    Enable socket backlog metric (only supported on Linux).
+
+    .. versionadded:: 23.1
+    """
+
+
 class Procname(Setting):
     name = "proc_name"
     section = "Process Naming"

diff --git a/gunicorn/sock.py b/gunicorn/sock.py
@@ -93,19 +93,22 @@ def set_options(self, sock, bound=False):
         sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
         return super().set_options(sock, bound=bound)
 
-    def get_backlog(self):
-        if self.sock and PLATFORM == "linux":
-            # tcp_info struct from include/uapi/linux/tcp.h
-            fmt = 'B' * 8 + 'I' * 24
-            try:
-                tcp_info_struct = self.sock.getsockopt(socket.IPPROTO_TCP,
-                                                       socket.TCP_INFO, 104)
-                # 12 is tcpi_unacked
-                return struct.unpack(fmt, tcp_info_struct)[12]
-            except AttributeError:
-                pass
-
-        return None
+    if PLATFORM == "linux":
+        def get_backlog(self):
+            if self.sock:
+                # tcp_info struct from include/uapi/linux/tcp.h
+                fmt = 'B' * 8 + 'I' * 24
+                try:
+                    tcp_info_struct = self.sock.getsockopt(socket.IPPROTO_TCP,
+                                                           socket.TCP_INFO, 104)
+                    # 12 is tcpi_unacked
+                    return struct.unpack(fmt, tcp_info_struct)[12]
+                except AttributeError:
+                    pass
+            return 0
+    else:
+        def get_backlog(self):
+            return -1
 
 
 class TCP6Socket(TCPSocket):