Fix Redis socket timeout default

CHANGELOG.txt

@@ -1,3 +1,11 @@
+4.3.1 (unreleased)
+------------------
+
+* Set ``socket_timeout`` to ``None`` by default when decoding Redis hosts,
+  preserving the pre-redis-py 8 behavior required by ``RedisChannelLayer``
+  blocking receive calls.
+
+
 4.3.0 (2025-07-22)
 ------------------
 

README.rst

@@ -48,7 +48,12 @@ Set up the channel layer in your Django settings file like so:
         "default": {
             "BACKEND": "channels_redis.core.RedisChannelLayer",
             "CONFIG": {
-                "hosts": [("localhost", 6379)],
+                "hosts": [
+                    {
+                        "address": "redis://localhost:6379",
+                        "socket_timeout": None,
+                    }
+                ],
             },
         },
     }
@@ -72,8 +77,31 @@ Possible options for ``CONFIG`` are listed below.
 ~~~~~~~~~
 
 The server(s) to connect to, as either URIs, ``(host, port)`` tuples, or dicts conforming to `redis Connection <https://redis.readthedocs.io/en/stable/connections.html#async-client>`_.
-Defaults to ``redis://localhost:6379``. Pass multiple hosts to enable sharding,
-but note that changing the host list will lose some sharded data.
+Defaults to ``redis://localhost:6379`` with ``socket_timeout`` set to
+``None``. Pass multiple hosts to enable sharding, but note that changing the
+host list will lose some sharded data.
+
+``RedisChannelLayer`` requires ``socket_timeout`` to be ``None`` or greater
+than the layer's blocking receive timeout. ``redis-py`` 8 changes the default
+``socket_timeout`` from ``None`` to ``5`` seconds, which can interrupt
+``RedisChannelLayer`` receive calls. Explicitly configure ``socket_timeout`` if
+you need a different Redis socket read timeout:
+
+.. code-block:: python
+
+    CHANNEL_LAYERS = {
+        "default": {
+            "BACKEND": "channels_redis.core.RedisChannelLayer",
+            "CONFIG": {
+                "hosts": [
+                    {
+                        "address": REDIS_URL,
+                        "socket_timeout": None,
+                    }
+                ],
+            },
+        },
+    }
 
 SSL connections that are self-signed (ex: Heroku):
 

channels_redis/utils.py

@@ -52,7 +52,7 @@ def decode_hosts(hosts):
     """
     # If no hosts were provided, return a default value
     if not hosts:
-        return [{"address": "redis://localhost:6379"}]
+        return [{"address": "redis://localhost:6379", "socket_timeout": None}]
     # If they provided just a string, scold them.
     if isinstance(hosts, (str, bytes)):
         raise ValueError(
@@ -63,11 +63,13 @@ def decode_hosts(hosts):
     result = []
     for entry in hosts:
         if isinstance(entry, dict):
-            result.append(entry)
+            host = entry.copy()
         elif isinstance(entry, (tuple, list)):
-            result.append({"host": entry[0], "port": entry[1]})
+            host = {"host": entry[0], "port": entry[1]}
         else:
-            result.append({"address": entry})
+            host = {"address": entry}
+        host.setdefault("socket_timeout", None)
+        result.append(host)
     return result
 
 

tests/test_core.py

@@ -419,12 +419,10 @@ def test_repeated_group_send_with_async_to_sync(channel_layer):
         pytest.fail(f"repeated async_to_sync wrapped group_send calls raised {exc}")
 
 
-@pytest.mark.xfail(
-    reason="""
+@pytest.mark.xfail(reason="""
 Fails with error in redis-py: int() argument must be a string, a bytes-like
 object or a real number, not 'NoneType'. Refs: #348
-"""
-)
+""")
 @pytest.mark.asyncio
 async def test_receive_cancel(channel_layer):
     """

tests/test_sentinel.py

@@ -461,12 +461,10 @@ async def test_group_send_capacity_multiple_channels(channel_layer, caplog):
         )
 
 
-@pytest.mark.xfail(
-    reason="""
+@pytest.mark.xfail(reason="""
 Fails with error in redis-py: int() argument must be a string, a bytes-like
 object or a real number, not 'NoneType'. Refs: #348
-"""
-)
+""")
 @pytest.mark.asyncio
 async def test_receive_cancel(channel_layer):
     """

tests/test_utils.py

@@ -1,6 +1,6 @@
 import pytest
 
-from channels_redis.utils import _consistent_hash
+from channels_redis.utils import _consistent_hash, decode_hosts
 
 
 @pytest.mark.parametrize(
@@ -18,3 +18,32 @@
 )
 def test_consistent_hash_result(value, ring_size, expected):
     assert _consistent_hash(value, ring_size) == expected
+
+
+def test_decode_hosts_defaults_socket_timeout_to_none():
+    assert decode_hosts(None) == [
+        {"address": "redis://localhost:6379", "socket_timeout": None}
+    ]
+    assert decode_hosts(["redis://localhost:6379"]) == [
+        {"address": "redis://localhost:6379", "socket_timeout": None}
+    ]
+    assert decode_hosts([("localhost", 6379)]) == [
+        {"host": "localhost", "port": 6379, "socket_timeout": None}
+    ]
+
+
+def test_decode_hosts_preserves_explicit_socket_timeout():
+    hosts = [{"address": "redis://localhost:6379", "socket_timeout": 10}]
+
+    assert decode_hosts(hosts) == [
+        {"address": "redis://localhost:6379", "socket_timeout": 10}
+    ]
+
+
+def test_decode_hosts_does_not_mutate_host_dicts():
+    hosts = [{"address": "redis://localhost:6379"}]
+
+    assert decode_hosts(hosts) == [
+        {"address": "redis://localhost:6379", "socket_timeout": None}
+    ]
+    assert hosts == [{"address": "redis://localhost:6379"}]