how to consume previous messages in apache kafka

Question

I want to read particular messages from topic. For example there are 12000 messages in topic and I want to read from 2000 to 5000 only. Is there any provision in kafka ? or can I use java consumer code to read particular messages from a topic?

Answer 1

The Java consumer API provides you "seek" methods and more specifically the following one

seek(TopicPartition partition, long offset)

You can specify to read messages starting from the provided offset but you cannot provide an ending offset. The other thing is that specifying an offset is more partition related and for this reason, you have to provide the TopicPartition as the first parameter.

Consider that if the topic partition is compacted and/or some messages are deleted, the offsets are not sequential anymore so you can have some holes. So you should pay attention if you want to read from the message with offset 2000 to the one with offset 5000 or you want to read from the 2000th message to the 5000th message (in this case the ordinal position could be not equal to the offset, ie the 2000th message is at offset 2100 because 100 messages before it were deleted).