我在server.log中找到了这个：
[2016-03-29 18:24:59,349] INFO Scheduling log segment 3773408933 for log g17-4 for deletion. (kafka.log.Log)
[2016-03-29 18:24:59,349] INFO Scheduling log segment 3778380412 for log g17-4 for deletion. (kafka.log.Log)
[2016-03-29 18:24:59,403] WARN [ReplicaFetcherThread-3-4], Replica 2 for partition [g17,4] reset its fetch offset from 3501121050 to current leader 4's start offset 3501121050 (kafka.server.ReplicaFetcherThread)
[2016-03-29 18:24:59,403] ERROR [ReplicaFetcherThread-3-4], Current offset 3781428103 for partition [g17,4] out of range; reset offset to 3501121050 (kafka.server.ReplicaFetcherThread)
[2016-03-29 18:25:27,816] INFO Rolled new log segment for 'g17-12' in 1 ms. (kafka.log.Log)
[2016-03-29 18:25:35,548] INFO Rolled new log segment for 'g18-10' in 2 ms. (kafka.log.Log)
[2016-03-29 18:25:35,707] INFO Partition [g18,10] on broker 2: Shrinking ISR for partition [g18,10] from 2,4 to 2 (kafka.cluster.Partition)
[2016-03-29 18:25:36,042] INFO Partition [g18,10] on broker 2: Expanding ISR for partition [g18,10] from 2 to 2,4 (kafka.cluster.Partition)
复制的偏移量大于leader的偏移量，因此复制数据将被删除，然后从leader中复制数据。
但是在复制时，群集非常慢;由于卡夫卡没有回应，一些风暴拓扑失败。