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Posted to common-user@hadoop.apache.org by Nate Carlson <ha...@natecarlson.com> on 2008/03/25 21:54:23 UTC
Sharing Hadoop slave nodes between multiple masters?
Is it possible to have a single slave process jobs for multiple masters?
If not, I guess I'll just run multiple slaves on the same machines. ;)
(Trying to share slaves for our dev/staging/qa environments)
Thanks!
-Nate
Re: Sharing Hadoop slave nodes between multiple masters?
Posted by Nate Carlson <na...@natecarlson.com>.
On Wed, 26 Mar 2008, Amar Kamat wrote:
> There are two types of slaves and 2 corresponding masters in Hadoop. The
> 2 masters are Namenode and JobTracker while the slaves are datanodes and
> tasktrackers resp. Each slave when started has a hardcoded master
> information in the config that is passed to the slave during the
> start-up. So sharing would not be possible.
*nods*
That's kind of what I figured, but thought I'd ask in case someone else
has worked on this before.
> Yes. Seems like. But be sure to have a control on the number of tasks
> that can be run on the machine. Commonly used config is 4 maps and 4
> reducers for a (mapred) slave that is not shared (i.e per machine). Try
> to make sure that the total tasks that can be run simultaneously is
> descent enough. Amar
Yeah... in most cases, the environments won't be running their slaves at
the same time, so I'm not too worried about that. I'll see if I can work
out a way to set hard limits though.
Thanks!
------------------------------------------------------------------------
| nate carlson | natecars@natecarlson.com | http://www.natecarlson.com |
| depriving some poor village of its idiot since 1981 |
------------------------------------------------------------------------
Re: Sharing Hadoop slave nodes between multiple masters?
Posted by Amar Kamat <am...@yahoo-inc.com>.
On Tue, 25 Mar 2008, Nate Carlson wrote:
> Is it possible to have a single slave process jobs for multiple masters?
There are two types of slaves and 2 corresponding masters in Hadoop. The 2
masters are Namenode and JobTracker while the slaves are datanodes and
tasktrackers resp. Each slave when started has a hardcoded master
information in the config that is passed to the slave during the start-up.
So sharing would not be possible.
>
> If not, I guess I'll just run multiple slaves on the same machines. ;)
Yes. Seems like. But be sure to have a control on the number of tasks that
can be run on the machine. Commonly used config is 4 maps and 4 reducers
for a (mapred) slave that is not shared (i.e per machine). Try to make
sure that the total tasks that can be run simultaneously is descent
enough.
Amar
>
> (Trying to share slaves for our dev/staging/qa environments)
>
> Thanks!
>
> -Nate
>