A common use case is for calculating a "processing lag time" comparing the record's timestamp (when it was published/persisted) against the current time that the consumer 'consumed' it. In theory, the delta is 'how far behind' the consumer is, tho you can come up with a variety of reasons why this wouldn't actually be true.
On Fri, Jan 19, 2018 at 12:52 PM, 1095193...@qq.com <1095193...@qq.com> wrote: > kafka does not delete message when message is consumed, it will purge > message when this message is expired. I guess this timeStamp is for > checking whether message is expired. > > > > 1095193...@qq.com > > From: Jake Yoon > Date: 2018-01-19 11:46 > To: users > Subject: What's the use of timestamp in ProducerRecord? > Hi, I am very new to Kafka. > And I have a very basic question. > > Kafka doc says, > > *ProducerRecord > <https://kafka.apache.org/0100/javadoc/org/apache/kafka/clients/producer/ > ProducerRecord.html#ProducerRecord(java.lang.String,%20java.lang.Integer,% > 20java.lang.Long,%20K,%20V)>* > (String > <http://docs.oracle.com/javase/7/docs/api/java/lang/ > String.html?is-external=true> > topic, Integer > <http://docs.oracle.com/javase/7/docs/api/java/lang/ > Integer.html?is-external=true> > partition, Long > <http://docs.oracle.com/javase/7/docs/api/java/lang/ > Long.html?is-external=true> > timestamp, K > <https://kafka.apache.org/0100/javadoc/org/apache/kafka/clients/producer/ > ProducerRecord.html> > key, V > <https://kafka.apache.org/0100/javadoc/org/apache/kafka/clients/producer/ > ProducerRecord.html> > value) > > and I know the default timestamp is the current time. But I am not sure > what's the use of it. > > - Is it just to log when the record is added? > - How Kafka use it for? > - Are there any other uses of it? > - Can "Consumer" retrieves the timestamp of the "ProducerRecord"? > > Thanks, >
