Workflow + Globus Toolkit Update September 8, 2004 Allan Doyle, NASA adoyle@intl-interfaces.com

Workflow + Globus Toolkit Update

September 8, 2004

Allan Doyle, NASAAllan Doyle, NASA

adoyle@intl-interfaces.comadoyle@intl-interfaces.com

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AgendaAgenda

• Workflow activity• Globus Toolkit status• CA Activity (Yonsook)

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AgendaAgenda

• Workflow activity• Globus Toolkit status• CA Activity (Yonsook)

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Workflow ActivityWorkflow Activity

• Began in late 2003• Goal was to be able to chain

processing among participants in a single workflow

• Held a series of teleconferences• http://grid-tech.ceos.org/gridwiki/WorkflowTige

rTeam

(Ask for username/password)

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Workflow activity - 1Workflow activity - 1

• First, we learned about workflow and about CEOS Grid Participants’ workflow tools…

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Workflow overviewWorkflow overview

• The next slides are taken from Tech Team members’ presentations.

• Annotations that were added for this presentation look like this

Annotation box…

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What is a Workflow?What is a Workflow?

Dutch Space has renamed their

workflow tools to GridAssist…

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Workflow LevelsWorkflow Levels

Application Domain

Abstract Workflow

Concrete Workflow

Execution Environment

Application Component Selection

Resource SelectionData Replica Selection

Transformation Instance Selection

= Data Transfer

FFT

FFT filea

host2

host1Retry

Pick DifferentResources

Specify a DifferentWorkflow

copy host1://home/filea to host2://u1/file1

/usr/local/bin/fft /u1/file1

From Pegasus presentation by Ewa Deelman, ISI

This material was redrawn to enhance visibility, it’s

from Ewa Deelman’s workflow presentation…

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Typical Workflow EnvironmentTypical Workflow Environment

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Workflow exampleWorkflow example

This is a domain (or application level)

workflow…

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Workflow detailed exampleWorkflow detailed example

This is an abstract workflow…

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GMU Virtual Product ConceptGMU Virtual Product Concept

Virtual data concept requires workflow tools in

order to be built…

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Workflow progressionWorkflow progression

Different levels of workflow…

Domain… Abstract… Concrete…

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Workflow toolsWorkflow tools

• DutchSpace - Grid Assist– Developed in-house, workflow engine and

client tools. (Runs on Globus Toolkit 2.x)

• NCSA (UAH partner) - Open GCE Runtime Engine– Based on Apache Ant (not Globus dependent)

• ISI - Pegasus– Developed as part of Earth Systems Grid work

w/Argonne (Runs on Globus 2.x, 3.x?)

• GMU - GeoTree– Based on BPEL (Business Process Execution

Language) (Runs on Globus 3.2.x)

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Workflow Activity - 2Workflow Activity - 2

• Then we investigated workflow interoperability.

• The plan was to1. Ask participants for use cases2. Decompose use cases into workflow

patterns

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Use case descriptionsUse case descriptions

• Identifier• Description• Actors• Goal• Preconditions• Assumptions• Frequency

• Basic Course• Alternate Courses• Included Use

Cases• Extended Use

Cases• Issues• Decisions

Workflows can be derived from these descriptions of actions

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Workflow PatternsWorkflow Patterns

• http://tmitwww.tm.tue.nl/research/patterns/

• Provides a good explanation and definition of 21 workflow patterns.

• Next slide shows some of the simple ones as examples.

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Basic workflow patternsBasic workflow patterns

A B CSequence: B is started after A completes. C is started after B completes.

A ANDB

C

Parallel Split: B and C are begun any time after A has completed.

CANDA

B

Synchronization: C is not begun until A and B have both completed.

A XORB

C

Exclusive Choice: Following A, a choice is made to pursue B or C but not both.

CXORA

B

Simple Merge: C activated once for every completion of A or B

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Use case analysisUse case analysis

• Use cases were received from– USGS– UAH/NOMADS– Dutch Space

• USGS and UAH/NOMADS use cases were refined via teleconference + email

• All are available on Workflow web page

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Initial FindingsInitial Findings

• Workflow tools are a necessary component!– Grid applications are partioned into work units

that run on many machines.– Runtime error handling is a vital part of

workflow engine capability

• Grid workflows + tools are complex– Tools take a long time to learn– Grid workflows support complex processing

tasks

• Many (~30) different Grid workflow systems exist– Interoperability among workflow tools is

currently nonexistent

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Use case findings - 1Based on the USGS and NOMADS/UAH Use Cases

Use case findings - 1Based on the USGS and NOMADS/UAH Use Cases

• Found that use cases tended to have many “hands-on” steps where scientists would make choices– This is one of the key areas the Grid workflow

community has identified as needing work.

• Use of “formal” workflow tools may be more work than it’s worth for the use cases– Application projects are using the Grid mainly

for data transfer, not computing– Workflows include some automation areas

(reprojection, reformatting, subsetting).

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Use case findings - 2Based on the Dutch Space Application description

Use case findings - 2Based on the Dutch Space Application description

• Dutch Space application is well suited for formal tool

• Dutch Space has implemented their own tool in response to their need and the (then) lack of existing tools.

• OMI application has long processing chain (c.f. earlier slides)

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Workflow ConclusionsWorkflow Conclusions

• Workflow community is starting to talk about interoperable workflows– http://www.extreme.indiana.edu/groc/

ggf10-ww/index.html

• Perhaps cross-workflow interoperability is not an immediate need– A single workflow tool can be used to control

remote job execution without needing to interoperate with other workflow tools.

– CEOS Grid activity should wait until Application Projects have a clear need for cross-tool workflow interoperability before doing further work.

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AgendaAgenda

• Workflow activity• Globus Toolkit status• CA Activity (Yonsook)

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Globus Toolkit (GT) UpdateGlobus Toolkit (GT) Update

• Current GT version is 3.2– Most CEOS Globus users are still using 2.4

• GT version 4.0 release is scheduled for January 31, 2005– http://www-unix.globus.org/toolkit/GT4Facts/

• GT4 will be backwards compatible with GT3.2

• Next 5 slides taken from the presentation given in Tromso, also available at

http://grid-tech.ceos.org/gridwiki/GlobusVersions

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QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

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QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

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QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

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GT 4.0 schedule and contentGT 4.0 schedule and content

• Next two slides have material from http://www-unix.globus.org/toolkit/GT4Facts/

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GT4 Release ScheduleGT4 Release Schedule

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GT4 ComponentsGT4 Components

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Globus Toolkit RecommendationsGlobus Toolkit Recommendations

• If you are using– GT 2.4

• Migrate to 4.0• Don’t go to 3.2 as intermediate step

– GT 3.2• Migrate to 4.0• 4.0 will be backwards compatible

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AgendaAgenda

• Workflow activity• Globus Toolkit status• CA Activity (Yonsook)

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CA ActivityCA Activity

• Following earlier work on Certificate Authorities (CA), NASA IPG (Information Power Grid) volunteered to provide CA services for CEOS Grid.

• NASA IPG funding has been cut– CEOS Grid cannot rely on IPG CA

anymore

• We decided to establish a CEOS CA on a NASA machine at GSFC

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CA Activity - cont.CA Activity - cont.

• Ananth Rao has installed a test CA and has produced a Certificat Request tool similar to the one provided by IPG

• This tool will undergo further testing after WGISS-18

• Once we are satisfied with it, we will provide it to the CEOS Grid