Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Plain View
MapReduce >> mail # dev >> running Combiner for all the task on the node.


+
Suresh S 2013-01-02, 12:23
+
Harsh J 2013-01-02, 17:48
+
Mahesh Balija 2013-01-02, 12:44
+
Mahesh Balija 2013-01-02, 12:50
+
Suresh S 2013-01-02, 13:04
Copy link to this message
-
Re: running Combiner for all the task on the node.
Hi Suresh,

           I mean, in current approach combine phase will occur per mapper
instance only, but NOT per node.
           I think additional local shuffle and sort phase should happen so
that you can combine per node.

           But NOT really sure whether this can be achievable or not. You
can give a try and see whether you find any complications.

Thanks,
Mahesh Balija,
Calsoft Labs.

On Wed, Jan 2, 2013 at 6:34 PM, Suresh S <[EMAIL PROTECTED]> wrote:

> Definitely it will cost some overload. This lead to less intermediate
> movement and less time for reduce phase.  This benefit may improve the
> overall performance.
> *Regards*
> *S.Suresh,*
> *Research Scholar,*
> *Department of Computer Applications,*
> *National Institute of Technology,*
> *Tiruchirappalli - 620015.*
> *+91-9941506562*
>
>
> On Wed, Jan 2, 2013 at 6:20 PM, Mahesh Balija <[EMAIL PROTECTED]
> >wrote:
>
> > Continued,
> >
> > Also one more shuffle and sort phase should occur so that you can
> > merge/combine them properly.
> > So you should decide whether additional shuffle and sort phase will be
> > overhead in contrast with combine per node.
> >
> > Best,
> > Mahesh Balija,
> > Calsoft Labs.
> >
> > On Wed, Jan 2, 2013 at 6:14 PM, Mahesh Balija <
> [EMAIL PROTECTED]
> > >wrote:
> >
> > > Hi Suresh,
> > >
> > >                The combiner function will aggregate the data from a
> > single
> > > map instance. But NOT for all the maps running in a given node.
> > >                AFAIK As the maps will be running in the individual
> child
> > > JVMs, still the intermediate data need to be serialized (moved) so that
> > > your combiner can aggregate the data at Node level.
> > >
> > > Best,
> > > Mahesh Balija,
> > > Calsoft Labs.
> > >
> > >
> > >
> > > On Wed, Jan 2, 2013 at 5:53 PM, Suresh S <[EMAIL PROTECTED]> wrote:
> > >
> > >> Hello,
> > >>
> > >>       I think, running combiner function at node level (to combine all
> > the
> > >> map task output of the node) may reduce the intermediate data
> movement.
> > >>
> > >>      I don't know this technique is already available or not. Is it
> > worth
> > >> for working in this direction?
> > >> Any suggestions? Thanks in advance.
> > >> *Regards*
> > >> *S.Suresh,*
> > >> *Research Scholar,*
> > >> *Department of Computer Applications,*
> > >> *National Institute of Technology,*
> > >> *Tiruchirappalli - 620015.*
> > >> *+91-9941506562*
> > >>
> > >
> > >
> >
>
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB