Check if redis cluster mode is enabled

[sophiamariem]

redis-py-cluster version - 2.1.0

I am looking for a graceful way to check whether it is enabled. At the minute it will throw a RedisclusterException which is nice enough but then an AttributeError is thrown from upstream

Exception ignored in: <function Redis.__del__ at 0x7fd1ba7ac790>
Traceback (most recent call last):
  File "redis/client.py", line 885, in __del__
    self.close()
  File "redis/client.py", line 888, in close
    conn = self.connection
AttributeError: 'RedisCluster' object has no attribute 'connection'

I have found this ticket redis/redis-py#1339, I am already using 3.5.3

[Grokzen]

@sophiamariem Have you tried out the latest master commits to see if it is different in there? This error you write about should be fixed in there as if i run the following that is trying to connect to a redis-server instance that do not have cluster mode enabled i get the following stacktrace

>>> rc = RedisCluster(host="127.0.0.1", port=6379)
Traceback (most recent call last):
  File "/home/grok/code/github/redis-py-cluster/rediscluster/nodemanager.py", line 226, in initialize
    cluster_slots = r.execute_command("cluster", "slots")
  File "/home/grok/.virtualenvs/redis-py-cluster/lib/python3.9/site-packages/redis/client.py", line 901, in execute_command
    return self.parse_response(conn, command_name, **options)
  File "/home/grok/.virtualenvs/redis-py-cluster/lib/python3.9/site-packages/redis/client.py", line 915, in parse_response
    response = connection.read_response()
  File "/home/grok/.virtualenvs/redis-py-cluster/lib/python3.9/site-packages/redis/connection.py", line 756, in read_response
    raise response
redis.exceptions.ResponseError: This instance has cluster support disabled

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/grok/code/github/redis-py-cluster/rediscluster/client.py", line 368, in __init__
    pool = connection_pool_cls(
  File "/home/grok/code/github/redis-py-cluster/rediscluster/connection.py", line 160, in __init__
    self.nodes.initialize()
  File "/home/grok/code/github/redis-py-cluster/rediscluster/nodemanager.py", line 238, in initialize
    raise RedisClusterException("ERROR sending 'cluster slots' command to redis server: {0}".format(node))
rediscluster.exceptions.RedisClusterException: ERROR sending 'cluster slots' command to redis server: {'host': '127.0.0.1', 'port': 6379}

This error should server as a good answer to the core question that how to check if it is enabled. However this is not really a gracefull way to do it, but my only suggestion that if you need to check each individual redis-server instance is to use plain Redis object classes instead and connect to each node and just call INFO command or CLUSTER INFO and you should be able to find this out.

[sophiamariem]

Thank you for your reply. I did end up using the CLUSTER INFO command and that's clean enough :)