Back to original proposal: If client side grouping reveals that the batch of operations cannot be supported by 'limited cross row transactions', what should the user do ?
Cheers On Tue, Jan 17, 2012 at 1:49 PM, Ted Yu <[email protected]> wrote: > Whether Omid fits the bill is open to discussion. > > We should revisit HBASE-2315 and provide the support Flavio, et al need. > > Cheers > > > On Tue, Jan 17, 2012 at 1:41 PM, Lars George <[email protected]>wrote: > >> 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 >> >> >> >> >> >> >
