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HBase >> mail # user >> Hbase import Tsv performance (slow import)


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Re: Hbase import Tsv performance (slow import)
>. Is there a way that i can explicitly turn on WAL for bulk loading?
no..
How you generate the unique id?  Remember that initial steps wont need the
HBase cluster at all. MR generates the HFiles and the o/p will be in file
only..  Mappers also will write o/p to file...  Only thing is that some
mappers crashed.. So thin MR fw will run that mapper again on the same data
set.. Then the unique id will be different? I think you no need to worry
about data loss from Hbase side..  So WAL is not required..

-Anoop-
On Wed, Oct 24, 2012 at 10:58 AM, anil gupta <[EMAIL PROTECTED]> wrote:

> That's a very interesting fact. You made it clear but my custom Bulk Loader
> generates an unique ID for every row in map phase. So, all my data is not
> in csv or text. Is there a way that i can explicitly turn on WAL for bulk
> loading?
>
> On Tue, Oct 23, 2012 at 10:14 PM, Anoop John <[EMAIL PROTECTED]>
> wrote:
>
> > Hi Anil
> >                 In case of bulk loading it is not like data is put into
> > HBase one by one.. The MR job will create an o/p like HFile.. It will
> > create the KVs and write to file in order as how HFile will look like..
> The
> > the file is loaded into HBase finally.. Only for this final step HBase RS
> > will be used.. So there is no point in WAL there...  I am making it clear
> > for you?   The data is already present in form of raw data in some txt or
> > csv file  :)
> >
> > -Anoop-
> >
> > On Wed, Oct 24, 2012 at 10:41 AM, Anoop John <[EMAIL PROTECTED]>
> > wrote:
> >
> > > Hi Anil
> > >
> > >
> > >
> > > On Wed, Oct 24, 2012 at 10:39 AM, anil gupta <[EMAIL PROTECTED]
> > >wrote:
> > >
> > >> Hi Anoop,
> > >>
> > >> As per your last email, did you mean that WAL is not used while using
> > >> HBase
> > >> Bulk Loader? If yes, then how we ensure "no data loss" in case of
> > >> RegionServer failure?
> > >>
> > >> Thanks,
> > >> Anil Gupta
> > >>
> > >> On Tue, Oct 23, 2012 at 9:55 PM, ramkrishna vasudevan <
> > >> [EMAIL PROTECTED]> wrote:
> > >>
> > >> > As Kevin suggested we can make use of bulk load that goes thro WAL
> and
> > >> > Memstore.  Or the second option will be to use the o/p of mappers to
> > >> create
> > >> > HFiles directly.
> > >> >
> > >> > Regards
> > >> > Ram
> > >> >
> > >> > On Wed, Oct 24, 2012 at 8:59 AM, Anoop John <[EMAIL PROTECTED]>
> > >> wrote:
> > >> >
> > >> > > Hi
> > >> > >     Using ImportTSV tool you are trying to bulk load your data.
> Can
> > >> you
> > >> > see
> > >> > > and tell how many mappers and reducers were there. Out of total
> time
> > >> what
> > >> > > is the time taken by the mapper phase and by the reducer phase.
> >  Seems
> > >> > like
> > >> > > MR related issue (may be some conf issue). In this bulk load case
> > >> most of
> > >> > > the work is done by the MR job. It will read the raw data and
> > convert
> > >> it
> > >> > > into Puts and write to HFiles. MR o/p is HFiles itself. The next
> > part
> > >> in
> > >> > > ImportTSV will just put the HFiles under the table region store..
> > >>  There
> > >> > > wont be WAL usage in this bulk load.
> > >> > >
> > >> > > -Anoop-
> > >> > >
> > >> > > On Tue, Oct 23, 2012 at 9:18 PM, Nick maillard <
> > >> > > [EMAIL PROTECTED]> wrote:
> > >> > >
> > >> > > > Hi everyone
> > >> > > >
> > >> > > > I'm starting with hbase and testing for our needs. I have set
> up a
> > >> > hadoop
> > >> > > > cluster of Three machines and A Hbase cluster atop on the same
> > three
> > >> > > > machines,
> > >> > > > one master two slaves.
> > >> > > >
> > >> > > > I am testing the Import of a 5GB csv file with the importTsv
> > tool. I
> > >> > > > import the
> > >> > > > file in the HDFS and use the importTsv tool to import in Hbase.
> > >> > > >
> > >> > > > Right now it takes a little over an hour to complete. It creates
> > >> > around 2
> > >> > > > million entries in one table with a single family.
> > >> > > > If I use bulk uploading it goes down to 20 minutes.
> > >> > > >