Eureka注册流程（2）

最新推荐文章于 2022-08-26 15:45:09 发布

原创

最新推荐文章于 2022-08-26 15:45:09 发布 · 1.5k 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#Eureka

本文深入探讨Eureka的注册流程，包括AcceptorExecutor的AcceptorRunner和TaskExecutors的BatchWorkerRunnable线程的工作机制。内容涉及任务队列处理、批量与单个任务的区分、Semaphore信号量在批量任务中的作用，以及ReplicationTaskProcessor如何处理同步任务，通过http接口实现服务节点间的实例信息同步。

4. AcceptorExecutor#AcceptorRunner线程和TaskExecutors#BatchWorkerRunnable线程在初始化时作为守护线程启动，这里处理请求有批量和单个，但是共用一个AcceptorExecutor，只是参数maxBatchingSize不一样，AcceptorRunner#run，先判断线程有没有被强制停止，

 public void run() {
            long scheduleTime = 0;
            while (!isShutdown.get()) {
                try {
                    drainInputQueues();

                    int totalItems = processingOrder.size();

                    long now = System.currentTimeMillis();
                    if (scheduleTime < now) {
                        scheduleTime = now + trafficShaper.transmissionDelay();
                    }
                    if (scheduleTime <= now) {
                        assignBatchWork();
                        assignSingleItemWork();
                    }

                    // If no worker is requesting data or there is a delay injected by the traffic shaper,
                    // sleep for some time to avoid tight loop.
                    if (totalItems == processingOrder.size()) {
                        Thread.sleep(10);
                    }
                } catch (InterruptedException ex) {
                    // Ignore
                } catch (Throwable e) {
                    // Safe-guard, so we never exit this loop in an uncontrolled way.
                    logger.warn("Discovery AcceptorThread error", e);
                }
            }
        }

然后通过drainAcceptorQueue方法把acceptorQueue队列中的任务取出来放入pendingTasks和processingOrder，代表的意思就是把需要执行的任务都放入待执行任务队列中。

private boolean isFull() {
            return pendingTasks.size() >= maxBufferSize;
        }

private void drainInputQueues() throws InterruptedException {
            do {
                drainReprocessQueue();
                drainAcceptorQueue();

                if (!isShutdown.get()) {
                    // If all queues are empty, block for a while on the acceptor queue
                    if (reprocessQueue.isEmpty() && acceptorQueue.isEmpty() && pendingTasks.isEmpty()) {
                        TaskHolder<ID, T> taskHolder = acceptorQueue.poll(10, TimeUnit.MILLISECONDS);
                        if (taskHolder != null) {
                            appendTaskHolder(tas