Re: Placement groups

From: Justin Riley <no email>
Date: Wed, 16 May 2012 14:31:39 -0400

Hey Sergio/Ron,

StarCluster automatically creates a placement group when launching any
cluster compute instance type. If the instance type is not cluster
compute then it's only launched in the cluster's security group and not
the placement group. So in short only your cluster compute instances
will be on 10GigE. Unfortunately at this time this means your master
node needs to be a cluster compute instance in order to share NFS over
the 10GigE network.

HTH,

~Justin

On Tue, May 15, 2012 at 06:38:51PM -0700, Ron Chen wrote:
> I think I will need to leave this question to Justin _at_ MIT, as I am not familiar with the starcluster source code. (I am only a developer of Open Grid Scheduler, the open source Grid Engine.)
>
> However, you can still run jobs on the master machine. GE & NFS serving on the master do not use lots of CPU cycles.
>
> OTOH, if your jobs generate tons of data, then you might want to place the master on a CC1 or CC2 or else NFS serving is limited by not having the 10 GigE network.
>
>
>  -Ron
>
>
>
>
> ________________________________
> From: Sergio Mafra <sergiohmafra_at_gmail.com>
> To: Ron Chen <ron_chen_123_at_yahoo.com>
> Cc: "smafra_at_ons.org.br" <smafra_at_ons.org.br>; "starcluster_at_mit.edu" <starcluster_at_mit.edu>
> Sent: Tuesday, May 15, 2012 9:26 PM
> Subject: Re: Placement groups
>
>
> Nice to know. This leads to another question. If you mix c1 instances (for master) with cc instances (for nodes) you will probably be out of the 10 Gbps network since placement groups works only for cluster instances, right?
> So if you really need bandwidth you will have to provision all instances as cluster instances even though the master would not need to be that big.
>
> Sergio
>
> Em terça-feira, 15 de maio de 2012, Ron Chen escreveu:
>
> The answer is yes.
> >
> >If you grep the source, you will find references to create_placement_group(), get_placement_group() and many placement group functions in the starcluster source code.
> >
> >
> > -Ron
> >
> >
> >
> >
> >________________________________
> >From: Sergio Mafra <sergiohmafra_at_gmail.com>
> >To: "starcluster_at_mit.edu" <starcluster_at_mit.edu>
> >Sent: Tuesday, May 15, 2012 8:36 PM
> >Subject: [StarCluster] Placement groups
> >
> >
> >Does StarCluster deploy the cc instances on a placement group to take advantage of a 10 Gbps network?
> >
> >Best Regards,
> >
> >Sergio Mafra
> >
> >
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Received on Wed May 16 2012 - 14:31:46 EDT