Support client side caching with RedisCluster (#3102)

* sync

* fix mock_node_resp

* fix mock_node_resp_func

* fix test_handling_cluster_failover_to_a_replica

* fix test_handling_cluster_failover_to_a_replica

* async cluster and cleanup tests

* delete comment

Author: dvora-h

redis/asyncio/cluster.py

@@ -18,6 +18,12 @@
     Union,
 )
 
+from redis._cache import (
+    DEFAULT_BLACKLIST,
+    DEFAULT_EVICTION_POLICY,
+    DEFAULT_WHITELIST,
+    _LocalCache,
+)
 from redis._parsers import AsyncCommandsParser, Encoder
 from redis._parsers.helpers import (
     _RedisCallbacks,
@@ -267,6 +273,13 @@ def __init__(
         ssl_keyfile: Optional[str] = None,
         protocol: Optional[int] = 2,
         address_remap: Optional[Callable[[str, int], Tuple[str, int]]] = None,
+        cache_enable: bool = False,
+        client_cache: Optional[_LocalCache] = None,
+        cache_max_size: int = 100,
+        cache_ttl: int = 0,
+        cache_eviction_policy: str = DEFAULT_EVICTION_POLICY,
+        cache_blacklist: List[str] = DEFAULT_BLACKLIST,
+        cache_whitelist: List[str] = DEFAULT_WHITELIST,
     ) -> None:
         if db:
             raise RedisClusterException(
@@ -310,6 +323,14 @@ def __init__(
             "socket_timeout": socket_timeout,
             "retry": retry,
             "protocol": protocol,
+            # Client cache related kwargs
+            "cache_enable": cache_enable,
+            "client_cache": client_cache,
+            "cache_max_size": cache_max_size,
+            "cache_ttl": cache_ttl,
+            "cache_eviction_policy": cache_eviction_policy,
+            "cache_blacklist": cache_blacklist,
+            "cache_whitelist": cache_whitelist,
         }
 
         if ssl:
@@ -682,7 +703,6 @@ async def execute_command(self, *args: EncodableT, **kwargs: Any) -> Any:
         :raises RedisClusterException: if target_nodes is not provided & the command
             can't be mapped to a slot
         """
-        kwargs.pop("keys", None)  # the keys are used only for client side caching
         command = args[0]
         target_nodes = []
         target_nodes_specified = False
@@ -1039,16 +1059,24 @@ async def parse_response(
     async def execute_command(self, *args: Any, **kwargs: Any) -> Any:
         # Acquire connection
         connection = self.acquire_connection()
+        keys = kwargs.pop("keys", None)
 
-        # Execute command
-        await connection.send_packed_command(connection.pack_command(*args), False)
-
-        # Read response
-        try:
-            return await self.parse_response(connection, args[0], **kwargs)
-        finally:
-            # Release connection
+        response_from_cache = await connection._get_from_local_cache(args)
+        if response_from_cache is not None:
             self._free.append(connection)
+            return response_from_cache
+        else:
+            # Execute command
+            await connection.send_packed_command(connection.pack_command(*args), False)
+
+            # Read response
+            try:
+                response = await self.parse_response(connection, args[0], **kwargs)
+                connection._add_to_local_cache(args, response, keys)
+                return response
+            finally:
+                # Release connection
+                self._free.append(connection)
 
     async def execute_pipeline(self, commands: List["PipelineCommand"]) -> bool:
         # Acquire connection

redis/asyncio/connection.py

@@ -227,6 +227,10 @@ def __init__(
             _cache = None
         self.client_cache = client_cache if client_cache is not None else _cache
         if self.client_cache is not None:
+            if self.protocol not in [3, "3"]:
+                raise RedisError(
+                    "client caching is only supported with protocol version 3 or higher"
+                )
             self.cache_blacklist = cache_blacklist
             self.cache_whitelist = cache_whitelist
 

redis/cluster.py

@@ -167,6 +167,13 @@ def parse_cluster_myshardid(resp, **options):
     "ssl_password",
     "unix_socket_path",
     "username",
+    "cache_enable",
+    "client_cache",
+    "cache_max_size",
+    "cache_ttl",
+    "cache_eviction_policy",
+    "cache_blacklist",
+    "cache_whitelist",
 )
 KWARGS_DISABLED_KEYS = ("host", "port")
 
@@ -1060,7 +1067,6 @@ def execute_command(self, *args, **kwargs):
             list<ClusterNode>
             dict<Any, ClusterNode>
         """
-        kwargs.pop("keys", None)  # the keys are used only for client side caching
         target_nodes_specified = False
         is_default_node = False
         target_nodes = None
@@ -1119,6 +1125,7 @@ def _execute_command(self, target_node, *args, **kwargs):
         """
         Send a command to a node in the cluster
         """
+        keys = kwargs.pop("keys", None)
         command = args[0]
         redis_node = None
         connection = None
@@ -1147,14 +1154,18 @@ def _execute_command(self, target_node, *args, **kwargs):
                     connection.send_command("ASKING")
                     redis_node.parse_response(connection, "ASKING", **kwargs)
                     asking = False
-
-                connection.send_command(*args)
-                response = redis_node.parse_response(connection, command, **kwargs)
-                if command in self.cluster_response_callbacks:
-                    response = self.cluster_response_callbacks[command](
-                        response, **kwargs
-                    )
-                return response
+                response_from_cache = connection._get_from_local_cache(args)
+                if response_from_cache is not None:
+                    return response_from_cache
+                else:
+                    connection.send_command(*args)
+                    response = redis_node.parse_response(connection, command, **kwargs)
+                    if command in self.cluster_response_callbacks:
+                        response = self.cluster_response_callbacks[command](
+                            response, **kwargs
+                        )
+                    connection._add_to_local_cache(args, response, keys)
+                    return response
             except AuthenticationError:
                 raise
             except (ConnectionError, TimeoutError) as e:

tests/conftest.py

@@ -275,7 +275,7 @@ def _get_client(
         redis_url = request.config.getoption("--redis-url")
     else:
         redis_url = from_url
-    if "protocol" not in redis_url:
+    if "protocol" not in redis_url and kwargs.get("protocol") is None:
         kwargs["protocol"] = request.config.getoption("--protocol")
 
     cluster_mode = REDIS_INFO["cluster_enabled"]

tests/test_asyncio/conftest.py

@@ -69,10 +69,9 @@ async def client_factory(
         url: str = request.config.getoption("--redis-url"),
         cls=redis.Redis,
         flushdb=True,
-        protocol=request.config.getoption("--protocol"),
         **kwargs,
     ):
-        if "protocol" not in url:
+        if "protocol" not in url and kwargs.get("protocol") is None:
             kwargs["protocol"] = request.config.getoption("--protocol")
 
         cluster_mode = REDIS_INFO["cluster_enabled"]