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 Threaded View
Hadoop >> mail # user >> Hadoop streaming or pipes ..


Copy link to this message
-
Re: Hadoop streaming or pipes ..
It is a regular process, unless you explicitly say you want it to be java, which would be a bit odd to do, but possible.

--Bobby

On 4/5/12 3:14 PM, "Mark question" <[EMAIL PROTECTED]> wrote:

Thanks for the response Robert ..  so the overhead will be in read/write
and communication. But is the new process spawned a JVM or a regular
process?

Thanks,
Mark

On Thu, Apr 5, 2012 at 12:49 PM, Robert Evans <[EMAIL PROTECTED]> wrote:

> Both streaming and pipes do very similar things.  They will fork/exec a
> separate process that is running whatever you want it to run.  The JVM that
> is running hadoop then communicates with this process to send the data over
> and get the processing results back.  The difference between streaming and
> pipes is that streaming uses stdin/stdout for this communication so
> preexisting processing like grep, sed and awk can be used here.  Pipes uses
> a custom protocol with a C++ library to communicate.  The C++ library is
> tagged with SWIG compatible data so that it can be wrapped to have APIs in
> other languages like python or perl.
>
> I am not sure what the performance difference is between the two, but in
> my own work I have seen a significant performance penalty from using either
> of them, because there is a somewhat large overhead of sending all of the
> data out to a separate process just to read it back in again.
>
> --Bobby Evans
>
>
> On 4/5/12 1:54 PM, "Mark question" <[EMAIL PROTECTED]> wrote:
>
> Hi guys,
>  quick question:
>   Are there any performance gains from hadoop streaming or pipes over
> Java? From what I've read, it's only to ease testing by using your favorite
> language. So I guess it is eventually translated to bytecode then executed.
> Is that true?
>
> Thank you,
> Mark
>
>

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