Writes within a HBase row are atomic. Now, whichever write becomes the latest write(with the help of timestamp value) will prevail as the default value. If you set versions to more than 1 in column family, then you will be able to see both the values if you query for multiple versions.
HTH, Anil Gupta On Sun, Oct 23, 2016 at 12:02 PM, Manjeet Singh <manjeet.chand...@gmail.com> wrote: > Till now what i understand their is no update > > if two different thread try to update same record what happen > > first record insert with some version > second thread comes and change the version and its like a new insert with > some version > this process called MVCC > > If I am correct how hbase support MVCC mean any configuration for handlling > multiple thread at same time? > > On Mon, Oct 24, 2016 at 12:24 AM, Manjeet Singh < > manjeet.chand...@gmail.com> > wrote: > > > No I don't have 50 clients? I want to understand internal working of > Hbase > > in my usecase I have bulk update operation from spark job we have 7 > > different kafka pipeline and 7 spark job > > it might happen that my 2 0r 3 spark job have same rowkey for update > > > > > > > > On Mon, Oct 24, 2016 at 12:20 AM, Dima Spivak <dimaspi...@apache.org> > > wrote: > > > >> If your typical use case sees 50 clients simultaneously trying to update > >> the same row, then a strongly consistent data store that writes to disk > >> for > >> fault tolerance may not be for you. That said, such a use case seems > >> extremely unusual to me and I'd ask why you're trying to update the same > >> row in such a manner. > >> > >> On Sunday, October 23, 2016, Manjeet Singh <manjeet.chand...@gmail.com> > >> wrote: > >> > >> > Hi Dima, > >> > > >> > I didn't get ? point is assume I have 50 different client all having > >> same > >> > rowkey all want to update on same rowkey at same time now just tell > what > >> > will happen? who will get what value? > >> > > >> > Thanks > >> > Manjeet > >> > > >> > On Mon, Oct 24, 2016 at 12:12 AM, Dima Spivak <dimaspi...@apache.org > >> > <javascript:;>> wrote: > >> > > >> > > Unless told not to, HBase will always write to memory and append to > >> the > >> > WAL > >> > > on disk before returning and saying the write succeeded. That's by > >> design > >> > > and the same write pattern that companies like Apple and Facebook > have > >> > > found works for them at scale. So what's there to solve? > >> > > > >> > > On Sunday, October 23, 2016, Manjeet Singh < > >> manjeet.chand...@gmail.com > >> > <javascript:;>> > >> > > wrote: > >> > > > >> > > > Hi All, > >> > > > > >> > > > I have read below mention blog and it also said Hbase holds the > >> lock on > >> > > > rowkey level > >> > > > https://blogs.apache.org/hbase/entry/apache_hbase_ > >> > internals_locking_and > >> > > > (0) Obtain Row Lock > >> > > > (1) Write to Write-Ahead-Log (WAL) > >> > > > (2) Update MemStore: write each cell to the memstore > >> > > > (3) Release Row Lock > >> > > > > >> > > > > >> > > > SO question is how to solve this if I have very frequent update on > >> > Hbase > >> > > > > >> > > > Thanks > >> > > > Manjeet > >> > > > > >> > > > On Wed, Aug 17, 2016 at 9:54 AM, Manjeet Singh < > >> > > manjeet.chand...@gmail.com <javascript:;> > >> > > > <javascript:;>> > >> > > > wrote: > >> > > > > >> > > > > Hi All > >> > > > > > >> > > > > Can anyone help me about how and in which version of Hbase > support > >> > > Rowkey > >> > > > > lock ? > >> > > > > I have seen article about rowkey lock but it was about .94 > >> version it > >> > > > said > >> > > > > that if row key not exist and any update request come and that > >> rowkey > >> > > not > >> > > > > exist then in this case Hbase hold the lock for 60 sec. > >> > > > > > >> > > > > currently I am using Hbase 1.2.2 version > >> > > > > > >> > > > > Thanks > >> > > > > Manjeet > >> > > > > > >> > > > > > >> > > > > > >> > > > > -- > >> > > > > luv all > >> > > > > > >> > > > > >> > > > > >> > > > > >> > > > -- > >> > > > luv all > >> > > > > >> > > > >> > > > >> > > -- > >> > > -Dima > >> > > > >> > > >> > > >> > > >> > -- > >> > luv all > >> > > >> > >> > >> -- > >> -Dima > >> > > > > > > > > -- > > luv all > > > > > > -- > luv all > -- Thanks & Regards, Anil Gupta
