-Re: several doubts about region split?
yonghu 2013-07-17, 14:10
Thanks for your quick response!
For the question one, what will be the latency? How long we need to wait
until the daughter regions are again online?
On Wed, Jul 17, 2013 at 4:05 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
> bq. Does it mean the region which will be splitted is not available
> bq. What happened to the read and write requests to that region?
> The requests wouldn't be served by the hosting region server until daughter
> regions become online.
> Will try to dig up answer to question #2.
> In short, load balancer is supposed to offload one of the daughter regions
> if continuous write load incurs.
> On Wed, Jul 17, 2013 at 6:53 AM, yonghu <[EMAIL PROTECTED]> wrote:
> > 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
> > 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
> > is still there. Moreover, this approach will be a big problem if we use
> > HBase default split approach. Suppose we bulk load data into HBase
> > 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