Brady: Hopefully Nicolas answered your questions. We do use zookeeper for coordinating table schema changes. See the following JIRA: HBASE-7305. ZK based Read/Write locks for table operations
Cheers On Mon, Apr 8, 2013 at 8:34 AM, Nicolas Liochon <[email protected]> wrote: > HBASE-5541 is about rowlock. The master plays no role in this. This lock > does not have to be distributed, because, in bigtable/hbase architecture, > the rows are allocated to a single region / region server. This makes > things faster. > > Nicolas > > > On Mon, Apr 8, 2013 at 5:27 PM, Brady Zhong <[email protected] > >wrote: > > > Hi Nicolas, > > > > Thanks for your explanation. I know HBase uses ZeeKeeper as coordinated > > service but not a lock management service like Chubby. Like HBASE-5541 > > states, it seems the RegionServer controls the whole write process > > including providing row lock, region lock etc.. So I wonder why we don't > > use high available service like ZooKeeper creating, managing and > releasing > > lock? > > > > > > Brady > > > > On Mon, Apr 8, 2013 at 11:13 PM, Nicolas Liochon <[email protected]> > > wrote: > > > > > Hi, > > > > > > 1. Yes. Client applications can start/read/write even when there is no > > > master. > > > 2. HBase already uses ZooKeeper. > > > > > > You may want to have to look at the hbase reference guide ( > > > http://hbase.apache.org/book.html). > > > > > > Nicolas > > > > > > > > > On Mon, Apr 8, 2013 at 4:39 PM, Brady Zhong <[email protected] > > > >wrote: > > > > > > > Hi all, > > > > > > > > My name is Brady Zhong, a college student using HBase to develop our > > own > > > > project. Currently I confronted with a problem. Since we need some > kind > > > of > > > > high availability, we hope HBase can keep available even though the > > > HMaster > > > > goes down. Here're my questions: > > > > > > > > 1. Can HBase work during the node failure of HMaster? Can users write > > or > > > > read the database before the switch and recovery of HMaster? > > > > 2. Why not use Zookeeper as distributed lock service for HBase, like > > > Chubby > > > > for Google Big Table? > > > > > > > > Thanks very much for any help in advance. > > > > > > > > > > > > Best regards, > > > > Brady Zhong > > > > > > > > > >
