Hi Ted, Wouldn't Omid (https://github.com/yahoo/omid) help there? Or is that too broad? Just curious.
Lars On Jan 17, 2012, at 4:36 PM, Ted Yu wrote: > Can we collect use case for 'limited cross row transactions' first ? > > I have been thinking about (unlimited) multi-row transaction support in > HBase. It may not be a one-man task. But we should definitely implement it > someday. > > Cheers > > On Tue, Jan 17, 2012 at 1:27 PM, lars hofhansl <[email protected]> wrote: > >> I just committed HBASE-5203 (together with HBASE-3584 this implements >> atomic row operations). >> Although a relatively small patch it lays the groundwork for heterogeneous >> operations in a single WALEdit. >> >> The interesting part is that even though the code enforced the atomic >> operation to be a for single row, this is not required. >> It is enough if all involved KVs reside in the same region. >> >> I am not saying that we should add any high level concept to HBase (such >> as the EntityGroups of Megastore). >> >> But, with a slight addition to the API (allowing a grouping of multiple >> row operations) client applications have all the building blocks to do >> limited cross row atomic operations. >> The client application would be responsible for either correctly >> pre-splitting the table, or a custom balancer has to be provided. >> >> The operation would fail if the regionserver determines that it would need >> data from multiple region servers. >> >> I think this needs at least minimal support from HBase and cannot >> (efficiently or without adding more moving parts) by a client API only. >> >> >> Comments? Is this worth pursuing? If so, I'll file a jira and provide a >> patch. >> >> Thanks. >> >> >> -- Lars >> >>
