Dear all, >From the HBase reference book, it mentions that when RegionServer splits regions, it will offline the split region and then adds the daughter regions to META, opens daughters on the parent's hosting RegionServer and then reports the split to the Master.
I have a several questions: 1. What does offline means? Does it mean the region which will be splitted is not available anymore? What happened to the read and write requests to that region? 2. From the description, if I understand right it means that now the RegionServer will contain two Regions (One RegionServer for both daughter and parent regions ) instead of one RegionSever for daughter and one for parent. If it is, what are the benefits of this approach? Hot-spot problem is still there. Moreover, this approach will be a big problem if we use the HBase default split approach. Suppose we bulk load data into HBase cluster, initially every write request will be accepted by only one RegionServer. After some write requests, the RegionServer cannot response any write request as it reaches its disk volume threshold. Hence, some data must be removed from one RegionSever to the other RegionServer. The question is that why we don't do it at the region split time? Thanks! Yong
