[ISSUE #8428] fix naming subscribe bug when multiple NamingService (2.x)

[liqipeng]

Detail : #8428

[KomachiSion]

1. Please rebase develop, we has fixed the CI and IT problem.
2. Should we use an UUID to identity single Client(NamingService), not for each subscriber.

[liqipeng]

1. Please rebase develop, we has fixed the CI and IT problem.
2. Should we use an UUID to identity single Client(NamingService), not for each subscriber.

@KomachiSion 我的实现是使用UUID来标识一个NamingService的，notifierEventScope就是这个标识：

    private String notifierEventScope;

    public NacosNamingService(String serverList) throws NacosException {
        Properties properties = new Properties();
        properties.setProperty(PropertyKeyConst.SERVER_ADDR, serverList);
	@@ -87,11 +90,12 @@ private void init(Properties properties) throws NacosException {
        InitUtils.initSerialization();
        InitUtils.initWebRootContext(properties);
        initLogName(properties);

        this.notifierEventScope = UUID.randomUUID().toString();    // 每个NacosNamingService生成一个UUID标识事件通知作用域
        this.changeNotifier = new InstancesChangeNotifier(this.notifierEventScope);
        NotifyCenter.registerToPublisher(InstancesChangeEvent.class, 16384);
        NotifyCenter.registerSubscriber(changeNotifier);
        this.serviceInfoHolder = new ServiceInfoHolder(namespace, this.notifierEventScope, properties);
        this.clientProxy = new NamingClientProxyDelegate(this.namespace, serviceInfoHolder, properties, changeNotifier);
    }

[liqipeng]

1、Event增加了一个scope()，默认实现返回null；Subscriber增加了一个 scopeMatches 的扩展方法，用于判断事件的作用域是否匹配

    /**
     * Whether the event's scope matches current subscriber. Default implementation is all scopes matched.
     * If you override this method, it better to override related {@link com.alibaba.nacos.common.notify.Event#scope()}.
     *
     * @param event {@link Event}
     * @return Whether the event's scope matches current subscriber
     */
    public boolean scopeMatches(T event) {
        return event.scope() == null;   // 默认判断==null，但是可以由子类覆默认实现
    }

2、DefaultPublisher

    void receiveEvent(Event event) {
        final long currentEventSequence = event.sequence();
        
        if (!hasSubscriber()) {
            LOGGER.warn("[NotifyCenter] the {} is lost, because there is no subscriber.", event);
            return;
        }

        // Notification single event listener
        for (Subscriber subscriber : subscribers) {
            if (!subscriber.scopeMatches(event)) { // 这里执行scopeMatches来进行判断
                continue;
            }

            // Whether to ignore expiration events
            if (subscriber.ignoreExpireEvent() && lastEventSequence > currentEventSequence) {
                LOGGER.debug("[NotifyCenter] the {} is unacceptable to this subscriber, because had expire",

3、InstancesChangeNotifier实现了自己的scopeMatches

    @Override
    public boolean scopeMatches(InstancesChangeEvent event) {
        return this.eventScope.equals(event.scope());
    }

[codecov-commenter]

Codecov Report

Merging #8433 (49723de) into develop (7ca069d) will increase coverage by 0.06%.
The diff coverage is 85.00%.

@@              Coverage Diff              @@
##             develop    #8433      +/-   ##
=============================================
+ Coverage      41.13%   41.20%   +0.06%     
- Complexity      4379     4387       +8     
=============================================
  Files            873      873              
  Lines          31811    31825      +14     
  Branches        3706     3707       +1     
=============================================
+ Hits           13085    13113      +28     
+ Misses         17413    17398      -15     
- Partials        1313     1314       +1     

Impacted Files	Coverage Δ
.../alibaba/nacos/common/notify/DefaultPublisher.java	65.47% <0.00%> (-1.60%)	⬇️
...ibaba/nacos/common/notify/listener/Subscriber.java	75.00% <0.00%> (-25.00%)	⬇️
...libaba/nacos/client/naming/NacosNamingService.java	87.83% <100.00%> (+0.08%)	⬆️
...a/nacos/client/naming/cache/ServiceInfoHolder.java	76.52% <100.00%> (+0.20%)	⬆️
...acos/client/naming/event/InstancesChangeEvent.java	100.00% <100.00%> (ø)
...s/client/naming/event/InstancesChangeNotifier.java	82.35% <100.00%> (+2.35%)	⬆️
...in/java/com/alibaba/nacos/common/notify/Event.java	100.00% <100.00%> (ø)
...alibaba/nacos/client/config/impl/ClientWorker.java	50.78% <0.00%> (-0.20%)	⬇️
.../core/v2/event/publisher/NamingEventPublisher.java	75.00% <0.00%> (+1.25%)	⬆️
... and 3 more

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[liqipeng]

@KomachiSion

1. Please rebase develop, we has fixed the CI and IT problem.
2. Should we use an UUID to identity single Client(NamingService), not for each subscriber.

CI、IT问题已解决；
上面评论增加了此PR变更的思路说明

[KomachiSion]

@KomachiSion

1. Please rebase develop, we has fixed the CI and IT problem.
2. Should we use an UUID to identity single Client(NamingService), not for each subscriber.

CI、IT问题已解决； 上面评论增加了此PR变更的思路说明

OK, I will review it again.

[hj-545]

这个升级不是一个平滑的升级方案！
应该是使用按需实现的！我压根没有这样的需求，一升级client包（1.4.x --> 1.4.6），原来的订阅功能完全失效，而且也没有告警没有异常！

[liqipeng]

这个升级不是一个平滑的升级方案！ 应该是使用按需实现的！我压根没有这样的需求，一升级client包（1.4.x --> 1.4.6），原来的订阅功能完全失效，而且也没有告警没有异常！

确实是没考虑到NotifyCenter.registerSubscriber这个api订阅全局InstancesChangeEvent的场景。