OCC got into 0.18.0. See the package.html javadoc in o.a.h.h.client.transactional for setup/usage instructions.
My secondary index patch is not in the trunk (or release) yet. You can try it out here: https://issues.apache.org/jira/browse/HBASE-883. If you do try it out, please comment in the jira how it worked, how you like the API, etc. I attempt to respect transactional properties with the index updates, but this has not been thoroughly tested. cheers, -clint On Tue, Oct 7, 2008 at 3:54 PM, Ski Gh3 <[EMAIL PROTECTED]> wrote: > Two quick follow-up questions: > > Which version of hbase do we need to download in order to use to OCC > functionality?0.18.0? > I guess no setting is required by the user, where hregionserver was used > will now be transactionalregion, right? > > How can this be combined with secondary index? Didn't find the code for > that > in 0.18.0, is that still > work in progress? > > Thanks a lot! > > On Mon, Oct 6, 2008 at 2:26 PM, Clint Morgan <[EMAIL PROTECTED]> wrote: > > > I implemented the OCC functionality. Went that route because it seemed > > relatively straightforward and has acceptable performance for our > > workloads. > > Also I saw something somewhere that made me think that google was using > OCC > > for transactions in AppEngine. > > > > My intuition is that where the OCC approach really gets into trouble is > > when > > transactions start to frequently conflict (EG, when the "optimistic" hope > > no > > longer holds). Of course, as you increase the life of a transaction, you > > increase the probability it will conflict with another. > > > > I don't know enough about timstamp-, or MV-CCs to compare "scalability" > to > > the OCC approach. > > > > -clint > > > > On Mon, Oct 6, 2008 at 11:19 AM, Jaeyun Noh <[EMAIL PROTECTED]> wrote: > > > > > Hi, > > > > > > I looked at the source codes implemented to support Multi-region > > > transaction > > > feature. (HBASE-669) > > > It uses optimistic concurrency control. Did any guys consider other CC > > like > > > timestamp-based CC or multiversion CC? > > > > > > I think it's okay in read-dominated and relatively short transaction > > > workloads. In other case, is MVCC more scalable rather than OCC? > > > What do you think of pros/cons of other concurrency control schemes in > > > Hbase > > > transactions? > > > > > > Just I'm curious that hbase transaction uses other CCs or not. > > > > > > Regards, > > > Jaeyun Noh. > > > > > >
