[Enhancement] Consumer may wait shorter time after receive reset offset request

[bxfjb]

Before Creating the Enhancement Request

• I have confirmed that this should be classified as an enhancement rather than a bug/feature.

Summary

    public synchronized void resetOffset(String topic, String group, Map<MessageQueue, Long> offsetTable) {
        DefaultMQPushConsumerImpl consumer = null;
        try {
            ...

            ConcurrentMap<MessageQueue, ProcessQueue> processQueueTable = consumer.getRebalanceImpl().getProcessQueueTable();
            for (Map.Entry<MessageQueue, ProcessQueue> entry : processQueueTable.entrySet()) {
                MessageQueue mq = entry.getKey();
                if (topic.equals(mq.getTopic()) && offsetTable.containsKey(mq)) {
                    ProcessQueue pq = entry.getValue();
                    pq.setDropped(true);
                    pq.clear();
                }
            }

            try {
                TimeUnit.SECONDS.sleep(10);
            } catch (InterruptedException ignored) {
            }
            ...

Consumer need to wait fixed 10 seconds after recieve broker's reset offset request, which is neither elegant nor efficient. The current implementation could cause badly consumption pause with multiple and dense request. We may check each process queue's status with a max waiting time until they are all clear.

Motivation

To polish code implementation and avoid perhaps performance side effect.

Describe the Solution You'd Like

Implement a neat polling for every process queue.

Describe Alternatives You've Considered

More complicated logic like CountDownLatch may help too.

Additional Context

No response

[bxfjb]

And more, for now broker will invoke reset action for every client in the consumer instead of only notifing the related client, which is also a potential small flaw.