apache-kafka - KafkaProducer.close() 和 KafkaProducer.flush() 的区别

Question

查看文档，我不确定我是否理解使用 close() 之间的区别和 flush() .

这是flush()的文档

 * Invoking this method makes all buffered records immediately available to send (even if <code>linger.ms</code> is
 * greater than 0) and blocks on the completion of the requests associated with these records. The post-condition
 * of <code>flush()</code> is that any previously sent record will have completed (e.g. <code>Future.isDone() == true</code>).
 * A request is considered completed when it is successfully acknowledged
 * according to the <code>acks</code> configuration you have specified or else it results in an error.

和 close() 的文档:

 * This method waits up to <code>timeout</code> for the producer to complete the sending of all incomplete requests.
 * If the producer is unable to complete all requests before the timeout expires, this method will fail
 * any unsent and unacknowledged records immediately.

这是否意味着:

如果我使用 close() 并且内存缓冲区中有一些记录未决，它们甚至不会被尝试(与flush相比，它会尝试发送它们)？

如果我使用flush()，如果重试次数很大，它可能会“永远”阻塞？使用 close() 时，我有一个需要多长时间的上限？

我想如果我在 1. 中是对的，一个 acks=0 的生产者会得到一个记录的确认，如果它“不幸”被放置在内存队列中，甚至可能不会被尝试发布在调用 close() 之后立即。

Answer 1

如果您想继续使用生产者并等待发送消息，您可以使用flush else close。 Close with timeout value 将等待根据配置发送消息并收到 ack 直到超时值，然后关闭生产者