t8y2/dbx · error

invalid RocketMQ frame length: %d

Error message

invalid RocketMQ frame length: %d

What it means

readRemotingFrame reads the 4-byte big-endian length prefix of a RocketMQ remoting frame and rejects any length that is non-positive or exceeds the 64MiB safety cap. This guard prevents allocating huge buffers from corrupt, truncated, or non-RocketMQ streams. It indicates the connection is not delivering a valid RocketMQ remoting protocol stream.

Source

Thrown at agents/drivers/rocketmq/routing.go:249

		}
		encoded, err := command.Encode()
		if err != nil {
			return err
		}
		if _, err := destination.Write(encoded); err != nil {
			return err
		}
	}
}

func readRemotingFrame(reader io.Reader) ([]byte, error) {
	header := make([]byte, 4)
	if _, err := io.ReadFull(reader, header); err != nil {
		return nil, err
	}
	length := int(binary.BigEndian.Uint32(header))
	if length <= 0 || length > 64*1024*1024 {
		return nil, fmt.Errorf("invalid RocketMQ frame length: %d", length)
	}
	frame := make([]byte, 4+length)
	copy(frame, header)
	if _, err := io.ReadFull(reader, frame[4:]); err != nil {
		return nil, err
	}
	return frame, nil
}

func signCommand(command *remoting.RemotingCommand, accessKey, secretKey string) {
	if accessKey == "" && secretKey == "" {
		return
	}
	if command.ExtFields == nil {
		command.ExtFields = map[string]string{}
	}
	delete(command.ExtFields, "Signature")
	command.ExtFields["AccessKey"] = accessKey

View on GitHub (pinned to c0390bff16)

Solutions

1. Verify the configured broker address and port actually serve the RocketMQ remoting protocol (default 9876/10911), not an HTTP or console endpoint
2. Check for TLS/proxy interference: connect directly to the broker to see if the error disappears
3. Capture the first bytes of the stream (tcpdump/wireshark) to confirm a plausible length prefix
4. Upgrade/align driver and broker versions to ensure remoting protocol compatibility

Example fix

// before
addr := "localhost:8080" // console/HTTP port
client := admin.New(addr)
// after
addr := "localhost:9876" // broker remoting port
client := admin.New(addr)

// ensure addr points at the remoting port before connecting
u, err := net.ResolveTCPAddr("tcp", brokerAddr)
if err != nil || u.Port == 80 || u.Port == 8080 {
    return fmt.Errorf("brokerAddr %q does not look like a remoting endpoint", brokerAddr)
}

frame, err := readRemotingFrame(conn)
if err != nil {
    var protoErr *protocolError
    if errors.As(err, &protoErr) && strings.Contains(protoErr.Error(), "invalid RocketMQ frame length") {
        // reconnect to correct broker endpoint / reset stream
    }
    return err
}

When it happens

Trigger: Calling forward/readRemotingFrame against a socket whose stream is not a RocketMQ remoting response: garbage bytes, a truncated/corrupted header, an intermediate proxy speaking a different protocol, or a length field exceeding 64*1024*1024.

Common situations: Pointing the driver at the wrong port (e.g. HTTP/health endpoint instead of the remoting port 9876); a firewall or LB mangling the stream; reading from a TLS-wrapped connection without TLS setup; broker protocol/version mismatch.

Related errors

• ZooKeeper SASL response is truncated
• send ZooKeeper connect request: %w
• read ZooKeeper connect response: %w
• query consumer status for group %s on all masters: %w
• query consumer lag for group %s on all masters: %w

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/ae9d8393c4b90eed. Report an issue: GitHub.