Tuesday, July 17, 2012

The Large Synoptic Survey Telescope (LSST) Needs Your Opportunistic Cycles

OSG Resource Providers,

The LSST VO (http://www.lsst.org/lsst/) is looking for cycles. LSST is currently running on OSG resources using the North West Indiana Campus Grid (NWICG) VO as an umbrella VO for their activities. Eventually, we would like for all of the LSST work to be accounted to the LSST VO. Please take a look to see if your resource is enabled to allow LSST VO jobs, and if it is not please consider enabling it. Below is a description of the application. LSST jobs run already on the OSG and the LSST simulation group can work closely with the OSG support group and the resource providers in case of need. If you'd like to help please enable the LSST VO: we are happy to provide assistance if help is needed.

Thank you in advance for your participation,
Rob Quick
OSG Operations Coordinator

Gabriele Garzoglio
OSG Support team

John Peterson
LSST Photon Simulator Coordinator

About LSST simulations
The Large Synoptic Survey Telescope (LSST) will image a large area of the sky with each exposure. This will help it in accomplishing its science missions:
1.Probing dark energy and dark matter
2.Taking an inventory of the solar system
3.Exploring the transient optical sky
4.Mapping the Milky Way

One of the main features of the telescope is a 3.2 Gigapixel camera, which is anticipated to produce about 15TB of uncompressed image data a night. Another is its large mirror, which allows the telescope to quickly detect faint objects in a large area of the sky.

The OSG user support team and the LSST simulation group have collaborated in 2010 to port the LSST image simulation application to the OSG. Today, LSST simulation jobs "overspill" to OSG from Purdue whenever additional cycles are needed. Simulated images are used to refine and validate the data analysis software used to accomplish LSST scientific missions. For one exposure the software simulates the path of 1011 photons from their sources, through the atmosphere, the telescope optics, and to the CCDs.

LSST Simulation Execution on the OSG

The client supports following important features:

* integration with glideinWMS
* automatic recovery of jobs through glideinWMS
* full support for eviction of jobs, automatic suspend and restart of the job
* ~30 MB data stage in / stage out per job without a need to prestage data at sites
* 1-5 hours per job
* the "unit" of computation is a "visit" of the sky i.e. two 15 sec exposures of all 189 camera CCDs i.e. 378 jobs. This takes ~1000 CPU hours.

Benefits of running LSST Simulation on your Site

LSST simulation runs approximately monthly "bursts" of job "overspilling" from Purdue to OSG and other resources. These jobs will utilize idles cycles at your site that might otherwise not be utilized. At the same time, through the integration with GlideinWMS, the jobs will not flood any one site.