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From anil gupta <anilgupt...@gmail.com>
Subject Re: Hbase Row key lock
Date Sun, 23 Oct 2016 19:15:59 GMT
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.chandhok@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.chandhok@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 <dimaspivak@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.chandhok@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 <dimaspivak@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.chandhok@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.chandhok@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

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