The document provides an overview of the Science Gateway Group at Indiana University. It introduces the group members and describes their focus areas as developing open source software for cyberinfrastructure like Apache Rave and Apache Airavata. It discusses the group's work on extending collaborations with application scientists in various domains. The document also outlines possibilities for collaboration with the PTI CREST Lab on topics like scientific workflows and generalized execution frameworks.

1. Science Gateway Group
Overview
Marlon Pierce, Suresh Marru, Raminder
Singh
Presentation to PTI CREST Lab
May 2nd, 2012

2. IU Science Gateway Group Overview
• IU Science Gateway Group members
– Marlon Pierce: Group Lead
– Suresh Marru: Principal Software Architect
– Raminder Singh, Yu Ma, Jun Wang, Lahiru Gunathilake,
(Chathura Herath): Senior team members
– Five interns and research assistants
• NSF SDCI funding of Open Gateway Computing
Environments project
– TACC (M. Dahan), SDSC (N. Wilkins-Diehr), SDSU (M.
Thomas), NCSA (S. Pamidighantam), UIUC (S. Wang),
Purdue (C. Song), UTHSCSA (E. Brookes)
– XSEDE Extended Collaboration Support Services

3. Science Gateway Group Focus Areas
• Open source, open community software for
cyberinfrastructure
– Apache Rave: http://rave.apache.org
– (portal software)
– Apache Airavata: http://www.airavata.org
(workflow software)
• Extended collaborations with application
scientists
– Astronomy, astrophysics, biophysics, chemistry,
nuclear physics, bio informatics…

4. Science Gateways outreach &
democratize Research and Education
Research &
Lowering the barrier for using Education
complex end-to-end Community
Developers computational technologies
Researchers Democratize
Cyberinfrastructure Empower
Facilitate

5. Possibilities for Collaboration
• Scientific workflows exhibit a number of
distributed execution patterns.
– Not just DAGs.
– Workflow start as an abstraction, but need system,
application, library level interactions.
– We are trying to generalize our execution framework
over a number of applications.
– This is parallel, complementary to work in CREST.
• Collaborations can be mediated through Apache,
students’ independent study, targeted papers.

6. Apache Airavata
Open Community Software for
Scientific Workflows
airavara.org

7. Apache Airavata
• Science Gateway software framework to
– Compose, manage, execute, and monitor
computational workflows on Grids and Clouds
– Web service abstractions to legacy command line-
driven scientific applications
– Modular software framework to use as individual
components or as an integrated solution.
• More Information
– Airavata Web Site: airavata.org
– Developer Mailing Lists: airavata-
dev@incubator.apache.org

8. Apache Airavata High Level Overview

9. A Classic Scientific Workflow
• Workflows are composite applications built out of independent
parts.
– Executables wrapped as network accessible services
• Example: codes A, B, and C need to be executed in a specific
sequence.
– A, B, C: codes compiled and executable on a cluster, supercomputer,
etc. through schedulers.
• A, B, and C do not need to be co-located
• A, B, and C may be sequential or parallel
• A, B and C may have data or control dependencies
– Data may need to be staged in and out
• Some variations on ABC:
– Conditional execution branches, interactivity
– Dynamic execution resource binding
– Iterations (Do-while, For-Each) over all or parts of the sequence
– Triggers, events, data streams

10. Linked Environment for Atmospheric Discovery
Storms Forming
Forecast Model
Streaming
Observations Data Mining
Instrument Steering
Refine forecast grid
Envisioned by a multi-disciplinary team from
OU, IU, NCSA, Unidata, UAH, Howard, On-Demand
Millersville, Colorado State, RENCI Grid Computing

11. Open Grid/Gateway Computing
Environments Atmospheric LEAD, OLAM
Science
LEAD Molecular
GridChem,
ParamChem,
Chemistry
OREChem
GridChem
OGCE Bio Physics
Ultrascan
Re-engineer, OVP/
TeraGrid Generalize, RST/
MIG
User Portal Build, Test and BioVLAB, mCpG
Bio Informatics
Release
OGCE NMI & Astronomy ODI, DES-SimWG
SDCI Funding
Nuclear Physics LCCI
XSEDE ECSS Gateway
Projects Projects in the pipe
QuakeSim, VLAB,
Einstein Gateway
11

12. Realizing the Universe for the Dark Energy Survey (DES) Using XSEDE Support
Principal Investigators: Prof. August Evrard (University of Michigan), Prof. Andrey Kravtsov (University of Chicago)
Background & Explanation: The Dark
Energy Survey (DES) is an upcoming
international experiment that aims to
constrain the properties of dark energy
and dark matter in the universe using a
deep, 5000-square degree survey of
cosmic structure traced by galaxies.
To support this science, the DES
Fig. 1 The density of dark matter in a thin radial slice as seen by a Simulation Working Group is generating
synthetic observer located in the 8 billion light-year computational
volume. Image courtesy Matthew Becker, University of Chicago. expectations for galaxy yields in various
cosmologies. Analysis of these simulated
catalogs offers a quality assurance
capability for cosmological and
astrophysical analysis of upcoming DES
telescope data.
Our large, multi-staged computations are
a natural fit for workflow control atop
XSEDE resources.
Fig. 2: A synthetic 2x3 arcmin DES sky image showing galaxies, stars,
and observational artifacts. Courtesy Huan Lin, FNAL.

13. DES Component Description
Application
CAMB Code for Anisotropies in the Microwave Background is a serial
FORTRAN code that computes the power spectrum of dark matter
(simulation initial conditions). Output is a small ASCII file describing
the power spectrum.
2LPTic Second-order Lagrangian Perturbation Theory initial conditions
code is an MPI-based C code that computes the initial conditions for
the simulation from parameters and an input power spectrum
generated by CAMB. Output is a set of binary files that vary in size
from ~80-250 GB depending on the simulation resolution.
LGadget MPI based C code that uses a TreePM algorithm to evolve a
gravitational N-body system. The outputs of this step are system
state snapshot files, as well as light-cone files, and some properties
of the matter distribution, including the power spectrum at various
timesteps. The total output from LGadget depends on resolution
and the number of system snapshots stored, and approaches 10~TB
for large DES simulation boxes.
ADDGALS Creates a synthetic galaxy catalog for science analysis

14. Case Study: Dark Energy Survey
• Long running code: Based on simulation box
size L-gadget can run for 3 to 5 days using
more than 1024 cores on TACC Ranger.
• Do-While Construct: Restart service support is
needed to work around queue time
restrictions. Do-while construct was
developed to address the need.
• Data size and file transfer challenges: L-
gadget produces 10~TB for large DES
simulation boxes in system scratch so data
need to moved to persistent storage ASAP
• File system issues: More than 10,000
lightcone files are doing continues file I/O.
Ranger has one Luster metadata server to
serve 300 I/O nodes. Sometime metadata
server can’t fine these lightcone files, which
make simulations to stop. We have wasted
Figure: Processing steps to build a synthetic galaxy catalog.
~50k SU this month struggling with I/O issues Xbaya workflow currently controls the top-most element (N-
and to get recommendation to use MPI I/O body simulations) which consists of methods to sample a
cosmological power spectrum (ps), generating an initial set
of particles (ic) and evolving the particles forward in time
with Gadget (N-body). The remaining methods are run
manually on distributed resources.

16. Case Study: ParamChem
• ParamChem researchers try to optimize the geometry of
new molecules which may or may not converge with in a
given time or number of steps.
• Factors that include the mathematical convergence
issues in solutions for partial integro-differential
equations to potential shallowness of an energy
landscape.
• The intermediate outputs from model iterations can be
used to determine convergence.
Complex graph executions with support
for long running and interactive
executions to address non-deterministic
convergence problems.

17. Case Study: LCCI
• The Leadership Class Configuration Interaction (LCCI) project is targeted to
accurately predict properties of nuclei for astrophysical and fusion energy
processes.
– James Vary’s group at Iowa State
• One of the PetaScale Apps
– Use DOE INCITE and NSF Blue Waters awarded resources
– Currently using 55 million processor hours on ORNL Cray XK6 machine and Argonne
Blue Gene/P.
• Workflow Goals
– Democratizing science: Reduce the learning curve associated with running simulations
– Controlled access: avoid inappropriate use of super computing resources
– Reproducibility of results
– Avoiding waste: needless duplication; minimize erroneous use of codes and erroneous
exchanging of intermediate files
– Sustainability: Ensure long-term preservation of applications, configurations and results
– Provenance: Provide the ability to track down the provenance of results as well as reuse
previously completed results where applicable without recalculating
– Parametric sweeps: Allow components to run over a range of dataset such that
applications may produce richer simulations

18. Example Workflow: Nuclear Physics
Courtesy of collaboration with Prof. James Vary and team, Iowa State

19. Next Generation Workflow Systems
• Scientific workflow systems and compiled
workflow languages have focused on modeling,
scheduling, data movement, dynamic service
creation and monitoring of workflows.
• Building on these foundations we extend to a
interactive and flexible workflow systems.
– interactive ways of steering the workflow execution
– interpreted workflow execution model
– high level instruction set supporting diverse execution
patterns
– flexibility to execute individual workflow activity and
wait for further analysis.

20. Various State Changes can tap into
lower layers
Running Workflow
Ready
Node
Wai ng Load from
Node provenance
Running
Node
Failed Finished
Node Node
Finished
Workflow
Ready
Workflow
Stopped
Workflow
Paused
Workflow
Failed
Workflow

21. Uncertainties in Workflows
• Mathematical uncertainty:
– PDE’s may not converge for certain conditions
– Statistical techniques lead to nondeterministic results, propagation of
uncertainties.
– CLoser observation at computational output ensure acceptability of results.
• Domain uncertainty:
– Optimization execution patterns: Scenarios of running against range of
parameter values in an attempt to find the most appropriate input set.
– Initial execution providing estimate of the accuracy of the inputs and facilitating
further refinement.
– Outputs are diverse and nondeterministic
• Resource uncertainty:
– Failures in distributed systems are norm than an exception
– Transient failures can be retried if computation is side-effect free/Idempotent.
– Persistent failures require migration

22. Next Steps
• Workflow start as an abstraction, but need
system, application, library level interactions.
– We are trying to generalize our execution
framework over a number of applications.
– This is parallel, complementary to work in CREST.
• Collaborations can be mediated through
Apache, students’ independent study,
targeted papers.

23. Backup Slides

24. Apache Rave

25. Apache Rave
• Open Community Software for Enterprise Social
Networking, Shareable Web Components, and
Science Gateways
• Founding members:
• Mitre Software
• SURFnet
• Hippo Software
• Indiana University
• More information
• Project Website: http://rave.apache.org/
• Mailing List: dev@rave.apache.org
1

26. Gadget Dashboard
View
Gadget Store
View

27. Extending Rave for Science Gateways
• Rave is designed to be extended.
– Good design (interfaces, easily pluggable
implementations) and code organization are required.
– It helps to have a diverse, distributed developer
community
• How can you work on it if we can’t work on it?
• Rave is also packaged so that you can extend it
without touching the source tree.
• GCE11 paper presented 3 case studies for Science
Gateways

28. Apache Software Foundation and
Cyberinfrastructure

29. Why Apache for Gateway Software?
• Apache Software Foundation is a neutral playing field
– 501(c)(3) non-profit organization.
– Designed to encourage competitors to collaborate on
foundational software.
– Includes a legal cell for legal issues.
• Foundation itself is sustainable
– Incorporated in 1999
– Multiple sponsors (Yahoo, Microsoft, Google, AMD, Facebook,
IBM, …)
• Proven governance models
– Projects are run by Program Management Committees.
– New projects must go through incubation.
• Provides the social infrastructure for building communities.
• Opportunities to collaborate with other Apache projects
outside the usual CI world.

30. The Apache Way
• Projects start as incubators with 1 champion and several mentors.
– Making good choices is very important
• Graduation ultimately is judged by the Apache community.
– +1/-1 votes on the incubator list
• Good, open engineering practices required
– DEV mailing list design discussions, issue tracking
– Jira contributions
– Important decisions are voted on
• Properly packaged code
– Build out of the box
– Releases are signed
– Licenses, disclaimers, notices, change logs, etc.
– Releases are voted
• Developer diversity
– Three or more unconnected developers
– Price is giving up sole ownership, replace with meritocracy

31. Apache and Science Gateways
• Apache rewards projects for cross-pollination.
– Connecting with complementary Apache projects
strengthens both sides.
– New requirements, new development methods
• Apache methods foster sustainability
– Building communities of developers, not just users
– Key merit criterion
• Apache methods provide governance
– Incubators learn best practices from mentors
– Releases are peer-reviewed

32. Apache Contributions Aren’t Just
Software
• Apache committers and PMC members aren’t just
code writers.
• Successful communities also include
– Important users
– Project evangelists
– Content providers: documentation, tutorials
– Testers, requirements providers, and constructive
complainers
• Using Jira and mailing lists
– Anything else that needs doing.

33. Case Study: LEAD
• To create an Integrated, Scalable Geosciences
Framework, LEAD among things resulted in a
developing a flexible Scientific workflow system.
• The initial goal was to realize WOORDS: Workflow
Orchestration for On-Demand Real-Time
Dynamically-Adaptive System.
• The system enables execution of legacy scientific
codes and facilities sophisticated coupling while
interacting with data and provenance sub-systems.

34. Case Study: One Degree Imager
• A single investigation requires multiple night observations
• Each night takes hours of observations with multiple exposures
• An exposure is divided into 64 Orthogonal Transfer Array (OTAs)
• Each OTA is an 8x8 collection of 512x512 pixel CCD images.
• Reducing these data sets require workflow planning taking advantage of
system architectures.
• Currently we take advantage of threaded parallelism at node level
branching out to multiple node executions.

35. Pipeline Parallelization
Campaign TOP
...
Night/Filter FTR FTR
...
Exposures EXP EXP
...
OTAs OTA OTA

36. Illustrating Interactivity
Asynchronous Applica on
refinements Steering
Orchestra on level Interac ons Job Level Interac ons
Parametric Provenance Workflow Job launch, Checkpoint/
Sweeps Steering gliding Restart
Model
Mathema cal Domain Resource
Refinement
Uncertain es

37. Execution Patterns
Parametric Sweeps
Start Start
Level 0
4 instances X 4 à 16 outputs
Level 1
2instances X (4x4)à 32 outputs
Level 2
1 instance X (32x32)à 1024outputs
A B C Pruned Computation
Dot vs Cartisian
Start! Start
Level%
0!
!!
!!
!!
!!!!4x4!instances!!16!outputs!
! ! !
! ! ! !
Level 1
! 2x16 instances! 32 outputs
!
!
Level 2
!
1x256 instances! 256 outputs
A! B! C!

38. Interactivity Contd.
• Deviations during workflow execution that do not
affect the structure of the workflow
– dynamic change workflow inputs, workflow rerun.
interpreted workflow execution model.
– dynamic change in point of execution, workflow smart
rerun.
– Fault handling and exception models.
• Deviations that change the workflow DAG during
runtime
– Reconfiguration of activity.
– Dynamic addition of activities to the workflow.
– Dynamic remove or replace of activity to the workflow