Visualization as a Science Discovery ToolIssues and Concerns

Kelly Gaither

Director of Visualization/

Sr. Research Scientist

Texas Advanced Computing Center

September 8, 2011

Issues and Concerns– Maximizing Scientific Impact– Managing Data at Scale– Providing Resources at Scale– Ensuring Broad Accessibility/Developing

Ubiquitous Tools

Visualization Mantra

“The purpose of computing is insight not numbers.”-- R. W. Hamming (1961)

“The purpose of computing is insight not numbers.”-- R. W. Hamming (1961)

“The purpose of visualization is insight not pictures.”-- Ben Schneiderman (2005)

“The purpose of visualization is insight not pictures.”-- Ben Schneiderman (2005)

Maximizing Scientific Impact

Image: Greg P. Johnson, Romy Schneider, TACC Image: Adam Kubach, Karla Vega, Clint Dawson

Image: Karla Vega, Shaolie Hossain, Thomas J.R., HughesGreg Abram, Carsten Burstedde, Georg Stadler, Lucas C. Wilcox, James R. Martin, Tobin Isaac, Tan Bui-Thanh,and Omar Ghattas

Managing Data at Scale

Large-ScaleVisualization

Resource

Large-ScaleVisualization

Resource

HPCSystem

HPCSystem

DataArchive

DataArchive

DisplayDisplay

Remote SiteRemote SiteWide-AreaNetwork

Wide-AreaNetwork Local SiteLocal Site

PixelsPixels

MouseMouse

Where Does Technology Fit In?

• We have always used technology to create visualizations of what we see in our minds eye.

• What changes over time is the technology we use to do the visualization.

LonghornFirst NSF XD Visualization Resource

• 256 Dell Dual Socket, Quad Core Intel Nehalem Nodes

– 240 with 48 GB shared memory/node (6 GB/core)– 16 with 144 GB shared memory/node (18 GB/core)– 73 GB Local Disk– 2 Nvidia GPUs/Node (FX 5800 – 4GB RAM)

• ~13.5 TB aggregate memory• QDR InfiniBand Interconnect• Jobs launched through SGE

• ~6GB/s to scratch filesystem• ~6GB/s to Ranger filesystem

256 Nodes, 2048 Cores, 512 GPUs, 14.5 TB Memory

Kelly Gaither (PI), Valerio Pascucci, Chuck Hansen, David Ebert, John Clyne (Co-PI), Hank Childs

Hadoop on LonghornPI: Weijia Xu (UT LIFT Grant)

• Local Storage Expansion– 192 500GB 7.2k drives are installed on 48 R610

nodes on Longhorn (96 usable TB) – 112 146GB 15k drives are installed on 16 R710

nodes on Longhorn. (16 usable TB)

• /hadoop file system• Went in to production December 2010• 6 early user projects (text mining and information

retrieval)• 142k core hours from Dec to Feb

Longhorn Usage Modalities:

• Remote/Interactive Visualization– Highest priority jobs – Remote/Interactive capabilities facilitated through VNC– Run on 3 hour queue limit boundary

• GPGPU jobs– Run on a lower priority than the remote/interactive jobs– Run on a 12 hour queue limit boundary

• CPU jobs with higher memory requirements– Run on lowest priority when neither remote/interactive nor GPGPU

jobs are waiting in the queue– Run on a 12 hour queue limit boundary

Longhorn Queue Structure

Example: qsub -q normal -P vis

Software Available on Longhorn• Programming APIs: OpenGL, vtk (Not natively parallel)

– OpenGL – low level primitives, useful for programming at a relatively low level with respect to graphics

– VTK (Visualization Toolkit) – open source software system for 3D computer graphics, image processing, and visualization

– IDL

• Visualization Turnkey Systems – VisIt – free open source parallel visualization and graphical analysis

tool– ParaView – free open source general purpose parallel visualization

system– VAPOR – free flow visualization package developed out of NCAR– EnSight – commercial turnkey parallel visualization package targeted

at CFD visualization– Amira – commercial turnkey visualization package targeted at

visualizing scanned medical data (CAT scan, MRI, etc..)

Longhorn Visualization Portalportal.longhorn.tacc.utexas.edu

• Developed to provide easy access to Longhorn and abstract away complexities involved with command line access

• Leverages TeraGrid user portal codebase and employs a fraction of TGUP developers to ensure continuity

• Used for all in-person Longhorn training

Longhorn Visualization Portalportal.longhorn.tacc.utexas.edu

>3000 jobs submitted through the portal

Longhorn Visualization Portalportal.longhorn.tacc.utexas.edu

• Specify type of session

• Specify resolution of vnc session

• Specify number of nodes needed and the wayness of the nodes

• Provides graphic of machine load

Longhorn Visualization Portalportal.longhorn.tacc.utexas.edu

• Vnc session opens up in java enabled browser

• Behaves as if user had gotten a remote desktop into Longhorn.

EnVisionGreg Johnson, Brandt Westing

• Web-based visualization software that allows researchers to develop interactive visualizations intuitively.

• Currently integrated into the Longhorn Visualization Portal but can run independently.

• Began collaborations with ParaView team.

Summary

• Close collaborations with the science partners are key– User support

• Minimize data transfers if possible– Data stays in single location

• Scale resources effectively based on use cases

• Easy accessibility to and interaction with technologies encourages diverse communities participation

Questions?kelly@tacc.utexas.edu