Issue 1:
I have searched the issues of this repository and believe that this is not a duplicate.

I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

Dubbo version: 2.5.3

Operating System version: mac

Java version: 1.8.0_202

Steps to reproduce this issue

java编码方式重复初始化一个没有服务提供者的consumer

while (true) {
try {

ReferenceConfig<INoProvider> reference = new ReferenceConfig<>(); // #1
reference.setApplication(new ApplicationConfig("first-dubbo-client")); // #2
reference.setRegistry(new RegistryConfig("zookeeper://127.0.0.1:2181")); // #3
reference.setInterface(INoProvider.class); // #4
INoProvider noProvider = reference.get(); // #5
noProvider.say(); // #6

Thread.sleep(10);
} catch (Exception e) {
e.printStackTrace();
}
}

AbstractRegistry方法

public void register(URL url) {
if (url == null) {
throw new IllegalArgumentException("register url == null");
}
if (logger.isInfoEnabled()){
logger.info("Register: " + url);
}
registered.add(url);
}

AbstractRegistry内部的registered，subscribed，notified，都有重复添加的情况，因为URL的参数中带有timestamp key，每次的timestamp不同，URL的hashCode()方法并没有排除timestamp，导致能一直重复add

Issue 2:
I have searched the issues of this repository and believe that this is not a duplicate.

I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

Dubbo version: 2.7.4

Operating System version: Window7

Java version: jdk8

Steps to reproduce this issue

Using the quick start example

https://dubbo.apache.org/en-us/docs/user/quick-start.html

Pls. provide [GitHub address] to reproduce this issue.

No dependence on zkclient test success

What do you expected from the above steps？

Test failure

Consumer cannot call provider interface

provider start log:

十月 27, 2019 6:36:21 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh

信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1e397ed7: startup date [Sun Oct 27 18:36:21 CST 2019]; root of context hierarchy

十月 27, 2019 6:36:21 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions

信息: Loading XML bean definitions from class path resource [provider.xml]

十月 27, 2019 6:36:21 下午 org.apache.dubbo.common.logger.LoggerFactory info

信息: using logger: org.apache.dubbo.common.logger.jcl.JclLoggerAdapter

十月 27, 2019 6:36:22 下午 org.apache.dubbo.config.AbstractConfig info

信息: [DUBBO] The service ready on spring started. service: com.bessky.demo.DemoService, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:22 下午 org.apache.dubbo.config.AbstractConfig warn

警告: [DUBBO] There's no valid metadata config found, if you are using the simplified mode of registry url, please make sure you have a metadata address configured properly., dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:22 下午 org.apache.dubbo.config.AbstractConfig info

信息: [DUBBO] No valid ip found from environment, try to find valid host from DNS., dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:22 下午 org.apache.dubbo.config.AbstractConfig info

信息: [DUBBO] Export dubbo service com.bessky.demo.DemoService to local registry url : injvm://127.0.0.1/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&bind.ip=192.168.98.1&bind.port=20880&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&qos.enable=false&release=2.7.4&side=provider&timestamp=1572172582429, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:22 下午 org.apache.dubbo.config.AbstractConfig info

信息: [DUBBO] There's no valid monitor config found, if you want to open monitor statistics for Dubbo, please make sure your monitor is configured properly., dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:22 下午 org.apache.dubbo.config.AbstractConfig info

信息: [DUBBO] Register dubbo service com.bessky.demo.DemoService url dubbo://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&bind.ip=192.168.98.1&bind.port=20880&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&qos.enable=false&release=2.7.4&side=provider&timestamp=1572172582429 to registry registry://224.5.6.7:1234/org.apache.dubbo.registry.RegistryService?application=hello-world-app&dubbo=2.0.2&pid=8792&qos.enable=false&registry=multicast&release=2.7.4&timestamp=1572172582421, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:22 下午 org.apache.dubbo.qos.protocol.QosProtocolWrapper info

信息: [DUBBO] qos won't be started because it is disabled. Please check dubbo.application.qos.enable is configured either in system property, dubbo.properties or XML/spring-boot configuration., dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.remoting.transport.AbstractServer info

信息: [DUBBO] Start NettyServer bind /0.0.0.0:20880, export /192.168.98.1:20880, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.registry.multicast.MulticastRegistry info

信息: [DUBBO] Register: dubbo://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&release=2.7.4&side=provider&timestamp=1572172582429, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.registry.multicast.MulticastRegistry info

信息: [DUBBO] Send multicast message: register dubbo://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&release=2.7.4&side=provider&timestamp=1572172582429 to /224.5.6.7:1234, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.registry.multicast.MulticastRegistry info

信息: [DUBBO] Subscribe: provider://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&bind.ip=192.168.98.1&bind.port=20880&category=configurators&check=false&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&qos.enable=false&release=2.7.4&side=provider&timestamp=1572172582429, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.registry.multicast.MulticastRegistry info

信息: [DUBBO] Send multicast message: subscribe provider://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&bind.ip=192.168.98.1&bind.port=20880&category=configurators&check=false&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&qos.enable=false&release=2.7.4&side=provider&timestamp=1572172582429 to /224.5.6.7:1234, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.registry.multicast.MulticastRegistry info

信息: [DUBBO] Receive multicast message: register dubbo://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&release=2.7.4&side=provider&timestamp=1572172582429 from /127.0.0.1:1234, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:23 下午 org.apache.dubbo.registry.multicast.MulticastRegistry info

信息: [DUBBO] Receive multicast message: subscribe provider://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&bind.ip=192.168.98.1&bind.port=20880&category=configurators&check=false&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&qos.enable=false&release=2.7.4&side=provider&timestamp=1572172582429 from /127.0.0.1:1234, dubbo version: 2.7.4, current host: 192.168.98.1

十月 27, 2019 6:36:24 下午 org.apache.dubbo.registry.multicast.MulticastRegistry warn

警告: [DUBBO] Ignore empty notify urls for subscribe url provider://192.168.98.1:20880/com.bessky.demo.DemoService?anyhost=true&application=hello-world-app&bean.name=com.bessky.demo.DemoService&bind.ip=192.168.98.1&bind.port=20880&category=configurators&check=false&deprecated=false&dubbo=2.0.2&dynamic=true&generic=false&interface=com.bessky.demo.DemoService&methods=sayHello&pid=8792&qos.enable=false&release=2.7.4&side=provider&timestamp=1572172582429, dubbo version: 2.7.4, current host: 192.168.98.1