Ray init error

[Jordan-Haidee]

Traceback (most recent call last):
  File "/home/he/.local/share/uv/python/cpython-3.8.20-linux-x86_64-gnu/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/home/he/.local/share/uv/python/cpython-3.8.20-linux-x86_64-gnu/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/home/he/py-projects/MARLlib/examples/train.py", line 9, in <module>
    mappo.fit(env, model, stop={"timesteps_total": 1000000}, checkpoint_freq=100, share_policy="group")
  File "/home/he/py-projects/MARLlib/marllib/marl/__init__.py", line 316, in fit
    return run_cc(self.config_dict, env_instance, model_class, stop=stop)
  File "/home/he/py-projects/MARLlib/marllib/marl/algos/run_cc.py", line 62, in run_cc
    ray.init(local_mode=exp_info["local_mode"], num_gpus=exp_info["num_gpus"])
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/_private/client_mode_hook.py", line 105, in wrapper
    return func(*args, **kwargs)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/worker.py", line 888, in init
    _global_node = ray.node.Node(
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/node.py", line 248, in __init__
    self.start_head_processes()
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/node.py", line 905, in start_head_processes
    self.start_redis()
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/node.py", line 712, in start_redis
    process_infos) = ray._private.services.start_redis(
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/_private/services.py", line 866, in start_redis
    port, p = _start_redis_instance(
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/ray/_private/services.py", line 1069, in _start_redis_instance
    redis_client.config_set("maxclients",
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/commands/core.py", line 864, in config_set
    return self.execute_command("CONFIG SET", name, value, *args, **kwargs)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 559, in execute_command
    return self._execute_command(*args, **options)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 567, in _execute_command
    return conn.retry.call_with_retry(
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/retry.py", line 65, in call_with_retry
    fail(error)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 571, in <lambda>
    lambda error: self._disconnect_raise(conn, error),
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 555, in _disconnect_raise
    raise error
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/retry.py", line 62, in call_with_retry
    return do()
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 568, in <lambda>
    lambda: self._send_command_parse_response(
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 542, in _send_command_parse_response
    return self.parse_response(conn, command_name, **options)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/client.py", line 584, in parse_response
    response = connection.read_response()
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/connection.py", line 592, in read_response
    response = self._parser.read_response(disable_decoding=disable_decoding)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/_parsers/resp2.py", line 15, in read_response
    result = self._read_response(disable_decoding=disable_decoding)
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/_parsers/resp2.py", line 25, in _read_response
    raw = self._buffer.readline()
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/_parsers/socket.py", line 115, in readline
    self._read_from_socket()
  File "/home/he/py-projects/MARLlib/.venv/lib/python3.8/site-packages/redis/_parsers/socket.py", line 68, in _read_from_socket
    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
redis.exceptions.ConnectionError: Connection closed by server.

This happened when I run the demo:

from marllib import marl
# prepare env
env = marl.make_env(environment_name="mpe", map_name="simple_spread")
# initialize algorithm with appointed hyper-parameters
mappo = marl.algos.mappo(hyperparam_source="mpe")
# build agent model based on env + algorithms + user preference
model = marl.build_model(env, mappo, {"core_arch": "mlp", "encode_layer": "128-256"})
# start training
mappo.fit(env, model, stop={"timesteps_total": 1000000}, checkpoint_freq=100, share_policy="group")

I'm not familiar with ray framework. Could someone give some help?