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From anil gupta <anilgupt...@gmail.com>
Subject Re: Hbase Row key lock
Date Mon, 24 Oct 2016 00:55:55 GMT
Writes/Updates usually takes few milliseconds in HBase. So, in normal cases
lock wont be held for seconds.

On Sun, Oct 23, 2016 at 12:57 PM, Manjeet Singh <manjeet.chandhok@gmail.com>
wrote:

> Anil all information are correct I am talking about suppose I didn't set
> any version and I have very simple requirement to update if I found xyz
> record and if I hv few ETL process which are responsible for aggregate the
> data which is very common. ... why my hbase stuck if I try to update same
> rowkey... its mean its hold the lock for few second....
>
> On 24 Oct 2016 00:46, "anil gupta" <anilgupta84@gmail.com> wrote:
>
> > 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
> >
>



-- 
Thanks & Regards,
Anil Gupta

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