Hi, Jean and Jieshan, Are you saying client can directly contact region servers? Maybe I overlooked, but I think the client may need lookup regions by first contacting Zk as in figure 8-11 from definitive book(as attached)...
Nevertheless, if it is the case, to assign a global timestamp, what is the practical solutions in real production today? since it still needs some centralised facility.. Please enlighten me. thanks. Regards Yun On Tue, Apr 16, 2013 at 8:19 AM, Jean-Marc Spaggiari < jean-m...@spaggiari.org> wrote: > Hi Yun, > > If I understand you correctly, that mean that each time our are going to do > a put or a get you will need to call ZK first? > > Since ZK has only one master active, that mean that this ZK master will be > called for each HBase get/put? > > You are going to create a bottle neck there. I don't know how many RS you > have, but you will certainly hotspot you ZK server. I'm not sure it's a > good idea. > > JM > > 2013/4/16 yun peng <pengyunm...@gmail.com> > > > Hi, All, > > I'd like to add a global timestamp oracle on Zookeep to assign globally > > unique timestamp for each Put/Get issued from HBase cluster. The reason I > > put it on Zookeeper is that each Put/Get needs to go through it and > unique > > timestamp needs some global centralised facility to do it. But I am > asking > > how practical is this scheme, like anyone used in practice? > > > > Also, how difficulty is it to extend Zookeeper, or to inject code to the > > code path of HBase inside Zookeeper. I know HBase has Coprocessor on > region > > server to let programmer to extend without recompiling HBase itself. Does > > Zk allow such extensibility? Thanks. > > > > Regards > > Yun > > >
