Dia: Have you tried command in the following form in hbase shell ? hbase> t.get 'r1', {COLUMN => 'c1', TIMERANGE => [ts1, ts2], VERSIONS => 4}
Cheers On Fri, Jun 5, 2015 at 8:50 AM, Dia Kharrat <dkhar...@gmail.com> wrote: > Ted: Yes, I've already read the HBase documentation, but didn't find > anything that directly answered my question. My question was simply whether > it's possible to get cells with the same timestamp with concurrent Puts to > the same cell. > > Vlad: Thanks for the information. Yep, I've also noticed the behavior of > the last-write-wins when testing directly in hbase shell and writing out > two values to the same cell with an identical timestamp. > > So, I gather that an application writing to the same cell concurrently will > result in potential data loss when the write is at the exact same > millisecond, correct? For my use-case, I'm not necessarily looking for > uniqueness for the timestamp, but want to ensure I can still access all > versions of the cell, even ones with the same timestamp. > > Dia > > On Thu, Jun 4, 2015 at 7:05 PM, Vladimir Rodionov <vladrodio...@gmail.com> > wrote: > > > >> Please read http://hbase.apache.org/book.html#_store > > > > How does this answer original question? > > > > -Vlad > > > > On Thu, Jun 4, 2015 at 6:30 PM, Ted Yu <yuzhih...@gmail.com> wrote: > > > > > Dia: > > > Please read http://hbase.apache.org/book.html#_store > > > > > > Cheers > > > > > > On Thu, Jun 4, 2015 at 6:02 PM, Vladimir Rodionov < > > vladrodio...@gmail.com> > > > wrote: > > > > > > > Yes, last write wins (with higher sequenceId). MemStore will resolve > > this > > > > conflict and only the last > > > > put will be added eventually, unless ... between these two puts > > > MemStore's > > > > snapshot is created. > > > > I this case put #1 will be saved in a snapshot and eventually will > > make > > > it > > > > into a store file, but this is just my speculations. > > > > > > > > -Vlad > > > > > > > > On Thu, Jun 4, 2015 at 5:08 PM, Dia Kharrat <dkhar...@gmail.com> > > wrote: > > > > > > > > > I'm trying to confirm the behavior of HBase when there are > concurrent > > > > > writes to the same cell that happen at the exact same millisecond > and > > > not > > > > > providing a timestamp value to the Put operations (i.e. relying on > > > > current > > > > > time of region server). Is it possible that such concurrent writes > > > result > > > > > in a cell with an identical version value or does HBase have a > > > mechanism > > > > to > > > > > protect against that? > > > > > > > > > > If that's the case, my understanding is that last write wins, > > correct? > > > > > > > > > > Thanks, > > > > > Dia > > > > > > > > > > > > > > >