> With the new replication feature of 0.92 edits are streamed from one cluster > to another
Interesting, what does 'cluster' mean in this context? Typically with MySQL one would have 1 master (for writes) and N slave servers (for reads). Is this a similar use case for HBase replication? On Sun, Apr 17, 2011 at 12:46 PM, Andrew Purtell <[email protected]> wrote: > Jason, > >> Andrew, when you say this: >> >> > Because HBase is a DOT it can provide strongly consistent >> > and atomic operations on rows, because rows exist in only >> > one place at a time. >> >> This excludes the use of HBase replication? > > Yes. > > With the new replication feature of 0.92 edits are streamed from one cluster > to another. Row mutations will be consistent/atomic as they are applied at > the target, but of course the replication stream may lag for a number of > reasons. Therefore the row data according to the view of each cluster may be > different. > >> I'm curious as to where HBase replication places the duplicate(?) >> region blocks in HDFS? > > The edits are streamed from the WAL. WALs are rolled per usual but are kept > perhaps for a longer period of time; until all of their replication scoped > edits have been streamed to the target cluster. > >> Also currently is there pass the baton failover when a replicated >> region master fails? > > Yes. Via mechanisms mediated by ZooKeeper. But J-D could say more here. > > - Andy > >
