kafka按照时间戳获取offset

1.官网关于根据时间戳获取offset的介绍

Can I add new brokers dynamically to a cluster?

Yes, new brokers can be added online to a cluster. Those new brokers won't have any data initially until either some new topics are created or some replicas are moved to them using thepartition reassignment tool. 

How do I accurately get offsets of messages for a certain timestamp using OffsetRequest?

 

Kafka allows querying offsets of messages by time and it does so at segment granularity. The timestamp parameter is the unix timestamp and querying the offset by timestamp returns the latest possible offset of the message that is appended no later than the given timestamp. There are 2 special values of the timestamp - latest and earliest. For any other value of the unix timestamp,Kafka will get the starting offset of the log segment that is created no later than the given timestamp. Due to this, and since the offset request is served only at segment granularity, the offset fetch request returns less accurate results for larger segment sizes.

 

For more accurate results, you may configure the log segment size based on time (log.roll.ms) instead of size (log.segment.bytes). However care should be taken since doing so might increase the number of file handlers due to frequent log segment rolling.