Optimizing cluster initialization changing the checks for cluster-enabled flag (#3158)

* change if the cluster-mode is enabled by trying run CLUSTER SLOT insted of INFO

* fix typo

* fixing cluster mode is not enabled on this node tests

* remove changes on asyncio

* rename mock flag to be more consistent

* optimizing async cluster creation using CLUSTER SLOT command instead of INFO command

* fixing test. Before INFO and CLUSTER_SLOT was used for performing the connection, now only the CLUSTER_SLOT, so the total commands is minus 1

* remove dot at the end of string

* remove unecessary print from test

* fix lint problems

---------

Co-authored-by: Willian Moreira <willian.moreira@ifood.com.br>

Author: willianmrs

redis/asyncio/cluster.py

@@ -1253,13 +1253,12 @@ async def initialize(self) -> None:
         for startup_node in self.startup_nodes.values():
             try:
                 # Make sure cluster mode is enabled on this node
-                if not (await startup_node.execute_command("INFO")).get(
-                    "cluster_enabled"
-                ):
+                try:
+                    cluster_slots = await startup_node.execute_command("CLUSTER SLOTS")
+                except ResponseError:
                     raise RedisClusterException(
                         "Cluster mode is not enabled on this node"
                     )
-                cluster_slots = await startup_node.execute_command("CLUSTER SLOTS")
                 startup_nodes_reachable = True
             except Exception as e:
                 # Try the next startup node.

redis/cluster.py

@@ -1525,11 +1525,12 @@ def initialize(self):
                     )
                     self.startup_nodes[startup_node.name].redis_connection = r
                 # Make sure cluster mode is enabled on this node
-                if bool(r.info().get("cluster_enabled")) is False:
+                try:
+                    cluster_slots = str_if_bytes(r.execute_command("CLUSTER SLOTS"))
+                except ResponseError:
                     raise RedisClusterException(
                         "Cluster mode is not enabled on this node"
                     )
-                cluster_slots = str_if_bytes(r.execute_command("CLUSTER SLOTS"))
                 startup_nodes_reachable = True
             except Exception as e:
                 # Try the next startup node.

tests/test_asyncio/test_cluster.py

@@ -127,7 +127,9 @@ async def slowlog(r: RedisCluster) -> None:
     await r.config_set("slowlog-max-len", old_max_length_value)
 
 
-async def get_mocked_redis_client(*args, **kwargs) -> RedisCluster:
+async def get_mocked_redis_client(
+    cluster_slots_raise_error=False, *args, **kwargs
+) -> RedisCluster:
     """
     Return a stable RedisCluster object that have deterministic
     nodes and slots setup to remove the problem of different IP addresses
@@ -139,9 +141,13 @@ async def get_mocked_redis_client(*args, **kwargs) -> RedisCluster:
     with mock.patch.object(ClusterNode, "execute_command") as execute_command_mock:
 
         async def execute_command(*_args, **_kwargs):
+
             if _args[0] == "CLUSTER SLOTS":
-                mock_cluster_slots = cluster_slots
-                return mock_cluster_slots
+                if cluster_slots_raise_error:
+                    raise ResponseError()
+                else:
+                    mock_cluster_slots = cluster_slots
+                    return mock_cluster_slots
             elif _args[0] == "COMMAND":
                 return {"get": [], "set": []}
             elif _args[0] == "INFO":
@@ -2458,7 +2464,10 @@ async def test_init_slots_cache_cluster_mode_disabled(self) -> None:
         """
         with pytest.raises(RedisClusterException) as e:
             rc = await get_mocked_redis_client(
-                host=default_host, port=default_port, cluster_enabled=False
+                cluster_slots_raise_error=True,
+                host=default_host,
+                port=default_port,
+                cluster_enabled=False,
             )
             await rc.aclose()
         assert "Cluster mode is not enabled on this node" in str(e.value)
@@ -2719,10 +2728,9 @@ async def parse_response(
             async with r.pipeline() as pipe:
                 with pytest.raises(ClusterDownError):
                     await pipe.get(key).execute()
-
                 assert (
                     node.parse_response.await_count
-                    == 4 * r.cluster_error_retry_attempts - 3
+                    == 3 * r.cluster_error_retry_attempts - 2
                 )
 
     async def test_connection_error_not_raised(self, r: RedisCluster) -> None:

tests/test_cluster.py

@@ -151,7 +151,9 @@ def cleanup():
     r.config_set("slowlog-max-len", 128)
 
 
-def get_mocked_redis_client(func=None, *args, **kwargs):
+def get_mocked_redis_client(
+    func=None, cluster_slots_raise_error=False, *args, **kwargs
+):
     """
     Return a stable RedisCluster object that have deterministic
     nodes and slots setup to remove the problem of different IP addresses
@@ -164,8 +166,11 @@ def get_mocked_redis_client(func=None, *args, **kwargs):
 
         def execute_command(*_args, **_kwargs):
             if _args[0] == "CLUSTER SLOTS":
-                mock_cluster_slots = cluster_slots
-                return mock_cluster_slots
+                if cluster_slots_raise_error:
+                    raise ResponseError()
+                else:
+                    mock_cluster_slots = cluster_slots
+                    return mock_cluster_slots
             elif _args[0] == "COMMAND":
                 return {"get": [], "set": []}
             elif _args[0] == "INFO":
@@ -2654,7 +2659,10 @@ def test_init_slots_cache_cluster_mode_disabled(self):
         """
         with pytest.raises(RedisClusterException) as e:
             get_mocked_redis_client(
-                host=default_host, port=default_port, cluster_enabled=False
+                cluster_slots_raise_error=True,
+                host=default_host,
+                port=default_port,
+                cluster_enabled=False,
             )
             assert "Cluster mode is not enabled on this node" in str(e.value)