在不改变消费者代码的前提下，生产者怎样获取消费者的applicationName,ip?

思路：provider端的filter中扩展获取

途径：

1、IP可以通过RemoteHost直接获取 应用名是无法直接获取的，需要consumer传入，所2、以consumer也需要扩展一个filter。 以下是一个完整可用的，记录ip，appName，耗时的一对filter，请自行取用

@Activate(group = Constants.CONSUMER) public class LogTraceConsumerFilter implements Filter {

private static final Logger LOG = LoggerFactory.getLogger(LogTraceConsumerFilter.class);

@Override
public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    //手动设置consumer的应用名进attachment
    String application = invoker.getUrl().getParameter(Constants.APPLICATION_KEY);
    if (application != null) {
        RpcContext.getContext().setAttachment("dubboApplication", application);
    }

    Result result = null;
    String serverIp = null;
    long startTime = System.currentTimeMillis();
    try {
        result = invoker.invoke(invocation);
        serverIp = RpcContext.getContext().getRemoteHost();//这次返回结果是哪个ip
        return result;
    } finally {
        Throwable throwable = (result == null) ? null : result.getException();
        Object resultObj = (result == null) ? null : result.getValue();
        long costTime = System.currentTimeMillis() - startTime;
        LOG.info("[TRACE] Call {}, {}.{}() param:{}, return:{}, exception:{}, cost:{} ms!", serverIp, invoker.getInterface(), invocation.getMethodName(), invocation.getArguments(), resultObj, throwable, costTime);
    }
}

}

@Activate(group = Constants.PROVIDER) public class LogTraceProviderFilter implements Filter {

private static final Logger LOG = LoggerFactory.getLogger(LogTraceProviderFilter.class);

@Override
public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    //上游如果手动设置了consumer的应用名进attachment，则取出来打印
    String clientIp = RpcContext.getContext().getRemoteHost();//这次请求来自哪个ip
    String application = RpcContext.getContext().getAttachment("dubboApplication");
    String from = clientIp;
    if (!StringUtils.isEmpty(application)) {
        from = application+"("+clientIp+")";
    }

    LOG.info("[Trace]From {}, {}.{}() param:{}", from, invoker.getInterface(), invocation.getMethodName(), invocation.getArguments());
    return invoker.invoke(invocation);
}

}

关于更多详情我写了一个博客：http://jaskey.github.io/blog/2020/05/18/dubbo-filter-trace-consumer/

原回答者GitHub用户Jaskey