Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase >> mail # dev >> About distributed lock service in HBase


Copy link to this message
-
Re: About distributed lock service in HBase
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
> > > >
> > >
> >
>