alibaba/nacos · error · RuntimeException

can not find implementation of {} for type {}

Error message

can not find implementation of {} for type {}

What it means

Error "can not find implementation of {} for type {}" thrown in alibaba/nacos.

Source

Thrown at core/src/main/java/com/alibaba/nacos/core/remote/grpc/ConnectionGeneratorServiceDelegate.java:58

        System.getProperty("nacos.core.remote.connection.generator", "nacos");
    
    private ConnectionGeneratorService connectionGeneratorService = null;
    
    private static final Logger LOGGER =
        LoggerFactory.getLogger(ConnectionGeneratorServiceDelegate.class);
    
    private ConnectionGeneratorServiceDelegate() {
        for (ConnectionGeneratorService connectionGeneratorService : NacosServiceLoader
            .load(ConnectionGeneratorService.class)) {
            if (connectionGeneratorService.getType().equals(connectionGeneratorType)) {
                this.connectionGeneratorService = connectionGeneratorService;
                LoggerUtils.printIfInfoEnabled(LOGGER, "{} has been loaded, class: {}",
                    connectionGeneratorType, connectionGeneratorService.getClass().getName());
            }
        }
        
        if (Objects.isNull(connectionGeneratorService)) {
            throw new RuntimeException("can not find implementation of "
                + ConnectionGeneratorService.class.getName() + " for type "
                + connectionGeneratorType);
        }
    }
    
    private static final ConnectionGeneratorServiceDelegate INSTANCE =
        new ConnectionGeneratorServiceDelegate();
    
    public static ConnectionGeneratorServiceDelegate getInstance() {
        return INSTANCE;
    }
    
    public Connection getConnection(ConnectionMeta metaInfo, StreamObserver streamObserver,
        Channel channel) {
        return connectionGeneratorService.getConnection(metaInfo, streamObserver, channel);
    }
}

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Review the input and runtime state for connection generator impl missing, correct the reported problem, and retry.

When it happens

Trigger: Thrown at core/src/main/java/com/alibaba/nacos/core/remote/grpc/ConnectionGeneratorServiceDelegate.java:58 when the library encounters an invalid state.

Common situations: No connection generator implementation exists for the requested type.

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/639d1af9415aeea8. Report an issue: GitHub.