For now, yes, that is the plan. However, if it is done before HBase 2.0.0 beta and if it is proven to be solid, then we can discuss bringing it back to 2.0.0.
On Fri, Jun 23, 2017 at 6:12 AM, Sean Busbey <bus...@apache.org> wrote: > It'd be great to see this land. You only mention the master branch as > a merge target; is the assumption that this would only be a HBase 3.0+ > addition? > > On Thu, Jun 22, 2017 at 7:34 PM, Amit Patel <amit.pa...@cloudera.com> > wrote: > > Hi everyone, > > > > > > > > I'm Amit and I've been picking up on the past work on Hybrid Logical > Clocks > > (HBASE-14070 <https://issues.apache.org/jira/browse/HBASE-14070>) that > was > > done by Sai Teja Ranuva last summer. The most recent status of HLC on > HBase > > can be found here > > <https://docs.google.com/document/d/1n32DUKoL3LSoKQ1_ > NuF8TbQkZiZCwFhbHZ7JXRjg3oA/edit#> > > and a prior document by Enis Soztutar with discussion can be found here > > <https://docs.google.com/document/d/1LL2GAodiYi0waBz5ODGL4LDT4e_ > bXy8P9h6kWC05Bhw/edit#>. > > I think the effort is at a point where it makes sense to create a public > > branch. > > > > > > > > Currently the plan is to create a public branch and incrementally add on > > functionality and tests. Initially, core HLC would be introduced as a > > commit. From there, HLC would then be enabled for just the meta table > > (updating the clock on events like region open/close, recovery, > > replication, etc). Once we are fully confident that HLC at least works on > > the meta table then I anticipate it would be appropriate to merge with > the > > master branch. > > > > > > > > Follow up commits would extend the effort by: > > > > > > > > - > > > > Addition of a protobuf message called NodeTime that holds timestamp > > corresponding to a send event between nodes. > > - > > > > Addition of NodeTime as a field to messages sent between nodes for > > messages like requests and responses for region open/close. > > - > > > > Addition of integration tests that verify HLC works correctly with > > recovery, replication, region open, and region close. > > - > > > > Later enabling HLC on user tables (main barrier are tests that rely on > > client-side setting of timestamps for table mutations which would no > longer > > be allowed on an HLC table). > > > > > > > > Work that I have implemented under the outstanding work > > <https://docs.google.com/document/d/1n32DUKoL3LSoKQ1_ > NuF8TbQkZiZCwFhbHZ7JXRjg3oA/edit#heading=h.8x5d8iakmo8b> > > as a part of getting HLC working for user tables includes: > > > > > > > > - > > > > Mapping of time ranges from client GETs > > - > > > > Disallowing clients to set timestamps for HLC and System Monotonic > tables > > > > > > > > Feel free to chime in with any comments, suggestions, or other input. > > > > -- > > Amit > -- Amit
