diff options
| -rw-r--r-- | CHANGES | 2 | ||||
| -rw-r--r-- | README.md | 50 | ||||
| -rw-r--r-- | redis/cluster.py | 17 | ||||
| -rw-r--r-- | tests/test_cluster.py | 23 |
4 files changed, 88 insertions, 4 deletions
@@ -11,9 +11,9 @@ * Fix broken connection writer lock-up for asyncio (#2065) * Fix auth bug when provided with no username (#2086) * Fix missing ClusterPipeline._lock (#2189) + * Added dynaminc_startup_nodes configuration to RedisCluster * Fix reusing the old nodes' connections when cluster topology refresh is being done * Fix RedisCluster to immediately raise AuthenticationError without a retry - * 4.1.3 (Feb 8, 2022) * Fix flushdb and flushall (#1926) * Add redis5 and redis4 dockers (#1871) @@ -1006,6 +1006,7 @@ a slots cache which maps each of the 16384 slots to the node/s handling them, a nodes cache that contains ClusterNode objects (name, host, port, redis connection) for all of the cluster's nodes, and a commands cache contains all the server supported commands that were retrieved using the Redis 'COMMAND' output. +See *RedisCluster specific options* below for more. RedisCluster instance can be directly used to execute Redis commands. When a command is being executed through the cluster instance, the target node(s) will @@ -1245,6 +1246,55 @@ The following commands are not supported: Using scripting within pipelines in cluster mode is **not supported**. + +**RedisCluster specific options** + + require_full_coverage: (default=False) + + When set to False (default value): the client will not require a + full coverage of the slots. However, if not all slots are covered, + and at least one node has 'cluster-require-full-coverage' set to + 'yes,' the server will throw a ClusterDownError for some key-based + commands. See - + https://redis.io/topics/cluster-tutorial#redis-cluster-configuration-parameters + When set to True: all slots must be covered to construct the + cluster client. If not all slots are covered, RedisClusterException + will be thrown. + + read_from_replicas: (default=False) + + Enable read from replicas in READONLY mode. You can read possibly + stale data. + When set to true, read commands will be assigned between the + primary and its replications in a Round-Robin manner. + + dynamic_startup_nodes: (default=False) + + Set the RedisCluster's startup nodes to all of the discovered nodes. + If true, the cluster's discovered nodes will be used to determine the + cluster nodes-slots mapping in the next topology refresh. + It will remove the initial passed startup nodes if their endpoints aren't + listed in the CLUSTER SLOTS output. + If you use dynamic DNS endpoints for startup nodes but CLUSTER SLOTS lists + specific IP addresses, keep it at false. + + cluster_error_retry_attempts: (default=3) + + Retry command execution attempts when encountering ClusterDownError + or ConnectionError + + reinitialize_steps: (default=10) + + Specifies the number of MOVED errors that need to occur before + reinitializing the whole cluster topology. If a MOVED error occurs + and the cluster does not need to be reinitialized on this current + error handling, only the MOVED slot will be patched with the + redirected node. + To reinitialize the cluster on every MOVED error, set + reinitialize_steps to 1. + To avoid reinitializing the cluster on moved errors, set + reinitialize_steps to 0. + ### Author redis-py is developed and maintained by [Redis Inc](https://redis.com). It can be found [here]( diff --git a/redis/cluster.py b/redis/cluster.py index 1737ec7..c5b6c8d 100644 --- a/redis/cluster.py +++ b/redis/cluster.py @@ -482,6 +482,7 @@ class RedisCluster(AbstractRedisCluster, RedisClusterCommands): require_full_coverage=False, reinitialize_steps=10, read_from_replicas=False, + dynamic_startup_nodes=False, url=None, **kwargs, ): @@ -509,6 +510,14 @@ class RedisCluster(AbstractRedisCluster, RedisClusterCommands): stale data. When set to true, read commands will be assigned between the primary and its replications in a Round-Robin manner. + :dynamic_startup_nodes: 'bool' + Set the RedisCluster's startup nodes to all of the discovered nodes. + If true, the cluster's discovered nodes will be used to determine the + cluster nodes-slots mapping in the next topology refresh. + It will remove the initial passed startup nodes if their endpoints aren't + listed in the CLUSTER SLOTS output. + If you use dynamic DNS endpoints for startup nodes but CLUSTER SLOTS lists + specific IP addresses, keep it at false. :cluster_error_retry_attempts: 'int' Retry command execution attempts when encountering ClusterDownError or ConnectionError @@ -598,6 +607,7 @@ class RedisCluster(AbstractRedisCluster, RedisClusterCommands): startup_nodes=startup_nodes, from_url=from_url, require_full_coverage=require_full_coverage, + dynamic_startup_nodes=dynamic_startup_nodes, **kwargs, ) @@ -1283,6 +1293,7 @@ class NodesManager: from_url=False, require_full_coverage=False, lock=None, + dynamic_startup_nodes=False, **kwargs, ): self.nodes_cache = {} @@ -1292,6 +1303,7 @@ class NodesManager: self.populate_startup_nodes(startup_nodes) self.from_url = from_url self._require_full_coverage = require_full_coverage + self._dynamic_startup_nodes = dynamic_startup_nodes self._moved_exception = None self.connection_kwargs = kwargs self.read_load_balancer = LoadBalancer() @@ -1612,8 +1624,9 @@ class NodesManager: self.slots_cache = tmp_slots # Set the default node self.default_node = self.get_nodes_by_server_type(PRIMARY)[0] - # Populate the startup nodes with all discovered nodes - self.startup_nodes = tmp_nodes_cache + if self._dynamic_startup_nodes: + # Populate the startup nodes with all discovered nodes + self.startup_nodes = tmp_nodes_cache # If initialize was called after a MovedError, clear it self._moved_exception = None diff --git a/tests/test_cluster.py b/tests/test_cluster.py index 438ef73..0353323 100644 --- a/tests/test_cluster.py +++ b/tests/test_cluster.py @@ -673,7 +673,7 @@ class TestRedisClusterObj: def moved_redirect_effect(connection, *args, **options): # raise a timeout for 5 times so we'll need to reinitilize the topology - if count.val >= 5: + if count.val == 4: parse_response.side_effect = real_func count.val += 1 raise TimeoutError() @@ -2285,6 +2285,27 @@ class TestNodesManager: assert rc.get_node(host=default_host, port=7001) is not None assert rc.get_node(host=default_host, port=7002) is not None + @pytest.mark.parametrize("dynamic_startup_nodes", [True, False]) + def test_init_slots_dynamic_startup_nodes(self, dynamic_startup_nodes): + rc = get_mocked_redis_client( + host="my@DNS.com", + port=7000, + cluster_slots=default_cluster_slots, + dynamic_startup_nodes=dynamic_startup_nodes, + ) + # Nodes are taken from default_cluster_slots + discovered_nodes = [ + "127.0.0.1:7000", + "127.0.0.1:7001", + "127.0.0.1:7002", + "127.0.0.1:7003", + ] + startup_nodes = list(rc.nodes_manager.startup_nodes.keys()) + if dynamic_startup_nodes is True: + assert startup_nodes.sort() == discovered_nodes.sort() + else: + assert startup_nodes == ["my@DNS.com:7000"] + @pytest.mark.onlycluster class TestClusterPubSubObject: |