Yes, Jean-Marc Spaggiari is right. Performance is the big problem of this approach, though zookeeper can help you implement this.
Regards, Jieshan -----Original Message----- From: Jean-Marc Spaggiari [mailto:jean-m...@spaggiari.org] Sent: Tuesday, April 16, 2013 8:20 PM To: user@hbase.apache.org Subject: Re: How practical is it to add a timestamp oracle on Zookeeper 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 >
