[Halld-offline] computing model, alpha release

[Heyes Graham]

Physics division does maintain quite a few packages but it is done by gentleman's agreement, i.e. nobody is explicitly paid to support ROOT etc. The issue with GRID is that it is big and ugly enough that you will have to pay out someone (probably more than one) to support GRID at the JLab end if we are anything other than a client on someone else's GRID implementation.

Without putting words in his mouth I think that is what Chip was talking about at the end of last week. We should write down what resources we (Physics in 12 GeV era) expect to have available to us offsite, what rates we need to those sites and other related parameters. Again, implementation neutral so not explicitly GRID. If it turns out that GRID is the best way to go then so be it. The perennial argument is that it isn't worthwhile to the lab to pay salaries and overhead for a couple of people to support something unless it gives the lab access to resources that are at least greater than you could buy with the same funds. So at least that argument needs to be fleshed out. What exactly is on the non-JLab end of such a "GIRD"?

There'll probably be much discussion of this...

Graham

On Feb 15, 2011, at 2:53 pm, David Lawrence wrote:

> Hi Mark,
> 
>     This is a great start. I have one quick question: have we verified that the reconstruction rate for the 10^8 data is the same as the 10^7? Even though the event rate to disk will be the same, I can imagine the 10^8 data being busier and therefore, take longer to process. They are hopefully comparable, but we should verify it if it hasn't been already. 
> 
>     I'd also like to follow up a little on the discussion started a while back on the how the GRID is to be included in the computing plan. It seems clear that our collaborators feel this will be an important part of the GlueX experiment's operation. Chip has indicated though that supporting it from the JLab side has significant resource costs and must be clearly justified. Has there been any discussion as to what exactly these costs are? I thought from earlier conversations that this was a manpower cost on the JLab side, but at this point, I don't know what is required. The Physics Division maintains several software packages already (ROOT, CERNLIB, Xerces,...) are there additional resources besides software maintenance? I know the our original CDR called for something like an OC24 connection due to the anticipated high bandwidth usage. Are there other hardware costs involved?
> 
>     We'll need to start gathering cost information as we develop the benefit argument in order to make a valid cost-benefit analysis.
> 
> Regards,
> -David
> 
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