On Fri, Jan 28, 2011 at 1:15 PM, Bill Graham <[email protected]> wrote: > I also don't have a solid understanding of the responsibilities of > master, but it seems like it's job is really about managing regions > (i.e., coordinating splits and compactions, etc.) and updating ROOT > and META. Is that correct? > >
Yes. It hosts the balancer and does bootsrapping on cluster startup doing bulk initial assign. On server crash, it runs the recovery splitting WAL logs and getting regions back on line again. It does not run splits. That is done by the regionservers themselves. Regionservers inform master of the split when done so it can take account of new state when running balancer. We should do a write up on this. Let me put this on the doc queue. St.Ack
