redis/redis-py · error · ValueError

Command {command_name} not found in commands

Error message

Command {command_name} not found in commands

What it means

Raised by CommandsParser._is_keyless_command() when no subcommand is supplied but command_name is not a key in self.commands. This means the policy/keyless lookup is being run for a command the parser never received from COMMAND. Distinct from error 4 in that this fires during the keyless-policy computation loop rather than the routing get_keys() path.

Source

Thrown at redis/_parsers/commands.py:253

        Raises:
            ValueError
                If the specified subcommand is not found within the command or the
                specified command does not exist in the available commands.
        """
        if subcommand_name:
            for subcommand in self.commands.get(command_name)["subcommands"]:
                if str_if_bytes(subcommand[0]) == subcommand_name:
                    parsed_subcmd = self.parse_subcommand(subcommand)
                    return parsed_subcmd["first_key_pos"] <= 0
            raise ValueError(
                f"Subcommand {subcommand_name} not found in command {command_name}"
            )
        else:
            command_details = self.commands.get(command_name, None)
            if command_details is not None:
                return command_details["first_key_pos"] <= 0

            raise ValueError(f"Command {command_name} not found in commands")

    def get_command_policies(self) -> PolicyRecords:
        """
        Retrieve and process the command policies for all commands and subcommands.

        This method traverses through commands and subcommands, extracting policy details
        from associated data structures and constructing a dictionary of commands with their
        associated policies. It supports nested data structures and handles both main commands
        and their subcommands.

        Returns:
            PolicyRecords: A collection of commands and subcommands associated with their
            respective policies.

        Raises:
            IncorrectPolicyType: If an invalid policy type is encountered during policy extraction.
        """
        command_with_policies = {}

View on GitHub (pinned to da03cdc7e8)

Solutions

1. Avoid concurrent calls that reinitialize() the parser while another caller is computing policies; serialize topology refresh.
2. Validate command_name in self.commands before invoking _is_keyless_command.
3. Upgrade redis-py - later versions guard against the concurrent-clear race.
4. Recreate the CommandsParser if the underlying connection was reset.

Example fix

// before
parser._is_keyless_command("mycmd")  # ValueError if 'mycmd' missing

// after
if "mycmd" not in parser.commands:
    parser.initialize(redis_conn)
assert "mycmd" in parser.commands
parser._is_keyless_command("mycmd")

# Validate the command is in the cache before the keyless lookup
def assert_command_known(parser, name):
    if name not in parser.commands:
        parser.initialize(parser.redis_connection)
    if name not in parser.commands:
        raise KeyError(f"command '{name}' not in COMMAND output")

try:
    parser._is_keyless_command(name)
except ValueError as e:
    if "not found in commands" in str(e):
        parser.initialize(parser.redis_connection)  # refresh then retry once
        parser._is_keyless_command(name)

When it happens

Trigger: get_command_policies() iterating over self.commands and calling _is_keyless_command(command) for a name that was somehow removed from the dict concurrently; calling _is_keyless_command directly with a command name that COMMAND did not return; race where the cache was cleared mid-iteration.

Common situations: Concurrent reinitialize() clearing self.commands while another thread iterates; passing a stale command name captured before a reconnect; misbehaving module that mutates the parser's commands dict.

Related errors

• Subcommand {subcommand_name} not found in command {command_n
• {cmd_name.upper()} command doesn't exist in Redis commands
• Incorrect request policy type: {policy_type}
• Incorrect response policy type: {policy_type}
• Cannot identify slot number for command: {args[0]},it cannot

AI-assisted analysis of redis/redis-py@da03cdc7e8 (2026-08-04). Data as JSON: /data/errors/12663951e959bb20.json. Report an issue: GitHub.