On Tue, Feb 21, 2012 at 12:08 PM, Jean-Daniel Cryans <[email protected]>wrote:
> On Sun, Feb 19, 2012 at 1:45 PM, Mikael Sitruk <[email protected]> > wrote: > > During compaction the region is not out of service. > > According to documentation the max region size for V2 format is 20G > > And now the question: Assuming that 20G is the limit and the number of > > regions in a single RS should stay low < 500 it means that there is no > mean > > having RS with more than 10TB of storage to use by HBase (otherwise > > locality will not be achieve for some servers, i also assume that > > compression is used and therefore it compensate the need for additional > > space for replication)? > > If the max number of region per RS is smaller then the storage size is > even > > smaller. Is it correct? > > In the documentation 20GB is given as an example of a larger size that > can be supported, but nothing blocks you from going way higher than > that. I've done some import tests and had 100GB regions. It just takes > a while to compact the bigger files. > With no impact on Java GC going nuts? FB reported (a few months ago) it was bad to run a region-server with -Xmx larger than 15G or 16G. Unless its no longer true, wouldn't that be limiting factor for how large one should make regions? > > Also you can go over 500 regions, in fact one of our clusters has > 14,398 regions right now. It's just a pain to reassign everything when > HBase boots but this is an offline cluster. > > J-D >
