dubbo3 provider可以配置token

dubbo:
application:
name: merge-provider-1
qos-enable: false
protocol:
name: dubbo
port: 20880
registry:
address: zookeeper://${zookeeper.address:192.168.157.151}:2181
provider:
token: “true”

当token 配置为true的时候，通过代码public class ServiceConfig extends ServiceConfigBase {

的
private Map<String, String> buildAttributes(ProtocolConfig protocolConfig) 里的

  /**
         * Here the token value configured by the provider is used to assign the value to ServiceConfig#token
         */
        if (ConfigUtils.isEmpty(token) && provider != null) {
            token = provider.getToken();
        }

        if (!ConfigUtils.isEmpty(token)) {
            if (ConfigUtils.isDefault(token)) {
                map.put(TOKEN_KEY, UUID.randomUUID().toString());
            } else {
                map.put(TOKEN_KEY, token);
            }
        }

来生成token，可以看到这个是一个UUID的，多个provider实例会有不同token。

而consumer 是在类public class RpcInvocation implements Invocation, Serializable {

public RpcInvocation(Invocation invocation, Invoker<?> invoker) {
        this(invocation.getTargetServiceUniqueName(), invocation.getServiceModel(), invocation.getMethodName(), invocation.getServiceName(),
                invocation.getProtocolServiceKey(), invocation.getParameterTypes(), invocation.getArguments(),
                invocation.copyObjectAttachments(), invocation.getInvoker(), invocation.getAttributes(),
                invocation instanceof RpcInvocation ? ((RpcInvocation) invocation).getInvokeMode() : null);
        if (invoker != null) {
            URL url = invoker.getUrl();
            setAttachment(PATH_KEY, url.getPath());
            if (url.hasParameter(INTERFACE_KEY)) {
                setAttachment(INTERFACE_KEY, url.getParameter(INTERFACE_KEY));
            }
            if (url.hasParameter(GROUP_KEY)) {
                setAttachment(GROUP_KEY, url.getGroup());
            }
            if (url.hasParameter(VERSION_KEY)) {
                setAttachment(VERSION_KEY, url.getVersion("0.0.0"));
            }
            if (url.hasParameter(TIMEOUT_KEY)) {
                setAttachment(TIMEOUT_KEY, url.getParameter(TIMEOUT_KEY));
            }
            if (url.hasParameter(TOKEN_KEY)) {
                setAttachment(TOKEN_KEY, url.getParameter(TOKEN_KEY));
            }
            if (url.hasParameter(APPLICATION_KEY)) {
                setAttachment(APPLICATION_KEY, url.getApplication());
            }
        }
    }

里面通过consumer 的url来设置token，如下图

因此在多provider的情况下会导致token 不一致，会有如下错误

org.apache.dubbo.rpc.RpcException: Invalid token! Forbid invoke remote service interface org.apache.dubbo.samples.merge.api.MergeService method mergeResult() from consumer 192.168.157.1 to provider 192.168.157.1, consumer incorrect token is 8d0fb50e-3714-4d74-9ed9-e623842c3b6a

这个错误会导致provider 下线，因此慎用，如果一定要用那么就指定token的值，不用使用UUID产生。

github也有一个issue https://github.com/apache/dubbo/issues/8383。