redis/redis-py · error · ConnectionError

Error setting client name

Error message

Error setting client name

What it means

Raised as a ConnectionError when CLIENT SETNAME is sent during connect (because client_name was configured) but the server's response is not 'OK'. This indicates the server rejected the name, typically because it is invalid (too long, contains spaces) or the server does not support the command.

Source

Thrown at redis/connection.py:1207

                and self.handshake_metadata.get("proto") != self.protocol
            ):
                raise ConnectionError("Invalid RESP version")

        # Activate maintenance notifications for this connection
        # if enabled in the configuration
        # This is a no-op if maintenance notifications are not enabled
        self.activate_maint_notifications_handling_if_enabled(check_health=check_health)

        # if a client_name is given, set it
        if self.client_name:
            self.send_command(
                "CLIENT",
                "SETNAME",
                self.client_name,
                check_health=check_health,
            )
            if str_if_bytes(self.read_response()) != "OK":
                raise ConnectionError("Error setting client name")

        # Set the library name and version from driver_info
        try:
            if self.driver_info and self.driver_info.formatted_name:
                self.send_command(
                    "CLIENT",
                    "SETINFO",
                    "LIB-NAME",
                    self.driver_info.formatted_name,
                    check_health=check_health,
                )
                self.read_response()
        except ResponseError:
            pass

        try:
            if self.driver_info and self.driver_info.lib_version:
                self.send_command(

View on GitHub (pinned to da03cdc7e8)

Solutions

1. Use a short, alphanumeric client_name with no spaces.
2. Upgrade the Redis server to one supporting CLIENT SETNAME.
3. Omit client_name if naming is not required.

Example fix

// before
r = redis.Redis(host=h, client_name='my app name with spaces')
// after
r = redis.Redis(host=h, client_name='my-app')

def validate_client_name(name):
    if name is None:
        return name
    if len(name) > 100 or any(c.isspace() for c in name):
        raise ValueError('client_name must be short and contain no spaces')
    return name
client_name = validate_client_name(raw_name)

try:
    r = redis.Redis(host=h, client_name=raw_name)
    r.ping()
except redis.exceptions.ConnectionError as e:
    if 'setting client name' in str(e):
        r = redis.Redis(host=h)  # drop client_name
        r.ping()

When it happens

Trigger: Constructing redis.Redis(client_name='some name') where the name exceeds the server limit or contains disallowed characters; connecting to an ancient Redis that lacks CLIENT SETNAME. The check fires in on_connect after setting the name.

Common situations: Long/invalid client_name strings; names containing spaces or newlines; server version too old; dynamic name generation that produces illegal characters.

Related errors

• Invalid RESP version
• Error setting client name
• Invalid Database
• Invalid RESP version
• Invalid Database

AI-assisted analysis of redis/redis-py@da03cdc7e8 (2026-08-04). Data as JSON: /data/errors/ea4d5972a3a378a6.json. Report an issue: GitHub.