Increase maximum aiohttp connections to 4096 (#89611)

fixes #89408

homeassistant/helpers/aiohttp_client.py

@@ -39,6 +39,20 @@ SERVER_SOFTWARE = "{0}/{1} aiohttp/{2} Python/{3[0]}.{3[1]}".format(
 
 WARN_CLOSE_MSG = "closes the Home Assistant aiohttp session"
 
+#
+# The default connection limit of 100 meant that you could only have
+# 100 concurrent connections.
+#
+# This was effectively a limit of 100 devices and than
+# the supervisor API would fail as soon as it was hit.
+#
+# We now apply the 100 limit per host, so that we can have 100 connections
+# to a single host, but can have more than 4096 connections in total to
+# prevent a single host from using all available connections.
+#
+MAXIMUM_CONNECTIONS = 4096
+MAXIMUM_CONNECTIONS_PER_HOST = 100
+
 
 class HassClientResponse(aiohttp.ClientResponse):
     """aiohttp.ClientResponse with a json method that uses json_loads by default."""
@@ -261,7 +275,12 @@ def _async_get_connector(
     else:
         ssl_context = False
 
-    connector = aiohttp.TCPConnector(enable_cleanup_closed=True, ssl=ssl_context)
+    connector = aiohttp.TCPConnector(
+        enable_cleanup_closed=True,
+        ssl=ssl_context,
+        limit=MAXIMUM_CONNECTIONS,
+        limit_per_host=MAXIMUM_CONNECTIONS_PER_HOST,
+    )
     hass.data[key] = connector
 
     async def _async_close_connector(event: Event) -> None: