Failed to send data to Kafka: Expiring 89 record(s) ...30005 ms has passed since last append

2021-06-08 02:05:37 java.lang.Exception: Failed to send data to Kafka: Expiring 89 record(s) for XXXXXXXXXXXXXX: 30005 ms has passed since last append

at org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducerBase.checkErroneous(FlinkKafkaProducerBase.java:400)

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谷歌后，查询到：解释比较好！

消息在producer端发送时，是先保存在中间缓存中，组成批，如果批等了超过默认时间限制30s后，还没发送出去就会报这个异常，同时该批的消息都会从发送队列中删除掉（丢失）！

https://stackoverflow.com/questions/46750420/kafka-producer-error-expiring-10-records-for-topicxxxxxx-6686-ms-has-passed

This exception is occuring because you are queueing records at a much faster rate than they can be sent.【插入消息的速度远远超过发送消息的速度】

When you call the send method, the ProducerRecord will be stored in