hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Manjeet Singh <manjeet.chand...@gmail.com>
Subject Re: Hbase Row key lock
Date Mon, 24 Oct 2016 02:01:33 GMT
Anil its written it can hold lock upto 60 second. In my case my job get
stuck and many update for same rowkey cause fir bead health of hbase in cdh
5.8

On 24 Oct 2016 06:26, "anil gupta" <anilgupta84@gmail.com> wrote:

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

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message