Merge pull request #2813 from tdadela/fix_worker_disconnection_deadlo…

…ck_urlib3_gevent

Avoid deadlock in gevent/urllib3 connection pool (fixes worker heartbeat timeouts)

locust/__init__.py

@@ -10,11 +10,17 @@
         # dont show a massive callstack if trio is not installed
         os._exit(1)
 
-from gevent import monkey
-
 if not os.getenv("LOCUST_SKIP_MONKEY_PATCH", None):
+    from gevent import monkey, queue
+
     monkey.patch_all()
 
+    if not os.getenv("LOCUST_SKIP_URLLIB3_PATCH", None):
+        import urllib3
+
+        urllib3.connectionpool.ConnectionPool.QueueCls = queue.LifoQueue
+        # https://github.com/locustio/locust/issues/2812
+
 from ._version import version as __version__
 from .contrib.fasthttp import FastHttpUser
 from .debug import run_single_user