diff --git a/oslo_messaging/_drivers/pool.py b/oslo_messaging/_drivers/pool.py
index 774c3ab34..d8ae9ddff 100644
--- a/oslo_messaging/_drivers/pool.py
+++ b/oslo_messaging/_drivers/pool.py
@@ -100,6 +100,10 @@ class Pool(object):
                     self._current_size += 1
                     break
 
+                LOG.warning("Connection pool limit exceeded: "
+                            "current size %s surpasses max "
+                            "configured rpc_conn_pool_size %s",
+                            self._current_size, self._max_size)
                 wait_condition(self._cond)
 
         # We've grabbed a slot and dropped the lock, now do the creation