VisTrails

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.VisTrails

Second Provenance ChallengeTommy Ellkvist

David Koop

Juliana Freire

Joint work with:Erik Andersen, Steven P. Callahan, Emanuele Santos, Carlos E. Scheidegger, Cláudio Silva, and Huy T. Vo


are needed to see this picture.Outline VisTrails Introduction VisTrails Demo Provenance Model and API Challenge Results Issues and Future Work


are needed to see this picture.VisTrails Comprehensive provenance infrastructure

for computational tasks Support for exploratory tasks such as

visualization and data mining Workflows are iteratively refined as users

generate and test hypotheses New change-based provenance model

Uniformly captures data and workflow provenance


are needed to see this picture.Change-based Provenance Provenance is stored as a tree of actions

add module

add connection


are needed to see this picture.Provenance: Storing Actions Each change writes new actions to the tree

<action id=“27” prevId=“26” user=“dakoop” date=“2007-06-20”> <add what=“module” objectId=“12”> <module id=“12” name=“vtkProperty” cache=“1”> <location id=“17” x=“-7.0” y=“97.0”/> </module> </add> <add what=“connection” objectId=“13”> <connection id=“13”> <port type=“source” moduleId=“10”/> <port type=“destination” moduleId=“12”/> </connection> </add></action>


are needed to see this picture.Change-based Provenance Data provenance: where does a specific

data product come from? Workflow evolution: how has workflow

structure changed over time? Treat workflow versions as data–store

provenance of workflows


are needed to see this picture.Layered Provenance




are needed to see this picture.








are needed to see this picture.VisTrails Provenance Normalized information–no redundancy!

Each layer provides more specific information but refers to parent layers

Workflow EvolutionWorkflowExecution Extensible storage options

Support for both relational and XML Flexible annotation framework–users can

specify application-specific provenance information



Provenance for Reproducibility and Beyond

Infrastructure for querying and reusing provenance Query workflows by example Create workflows by analogy

Collaborative exploration Scalable derivation of data products


are needed to see this picture.VisTrails Demo



Supporting Different Provenance Backends

VisTrails has powerful tools to query and reuse provenance information

There are many powerful workflow systems that produce such information

Problem: How to integrate different provenance backends?

Our approach: A mediation-based approach to provenance interoperability


are needed to see this picture.Mediator Architecture

Mapping from global schema to data source specific schema


are needed to see this picture.Mediated Provenance

Mapping from general model to engine-specific model


are needed to see this picture.Combining Provenance Establish model Produce an API for this model Wrap provenance access for each

system so that queries become native over their provenance data


are needed to see this picture.Provenance Model Follows the layered architecture

Versions map to a workflows Workflows are modeled as graphs Parameters capture module state User-defined annotations are available at

each layer of the model Module Definition stores information about

the computational pieces


are needed to see this picture.Provenance Model


are needed to see this picture.Provenance API Implements common access queries and

operations over the provenance model Examples:

getParent(module)

getChildren(module)

getUpstream(module)

getDownstream(module)

getAnnotations(module | workflow | …)

getDataItems(module_exec)

getParameters(module)

getVersion(time)

getExecutedModules(workflow)

getConnection(data_item)

getPorts(connection)

findModulesByParameter(search_params)

findModulesByAnnotation(search_params)

findExecutionsByAnnotation(search_params)

findVersionsByModules(search_params)


are needed to see this picture.Provenance API Example

getExecutedModules(wf_exec)

VisTrails (XPath) def getExecutedModules(self, wf_exec): newdataitems = [] q = '//exec[@id="' + wf_exec.pid.key + '"]/@moduleId' dataitems = self.logcontext.xpathEval(q)

Pasoa (XPath)def getExecutedModules(self, wf_exec): q = "//ps:relationshipPAssertion[ps:localPAssertionId='" + wf_exec.pid.key + "']/ps:relation" dataitems = self.context.xpathEval(q)

Taverna (SPARQL)def getExecutedModules(self, wf_exec): " " q = ''' SELECT ?mi FROM <''' + self.path + '''> WHERE { <''' + wf_exec.pid.key + '''> <http://www.mygrid.org.uk/provenance#runsProcess> ?mi } ''' return self.processQueryAsList(q, pModuleInstance)


are needed to see this picture.Provenance API Results Implemented queries for each system

and a combination of all three Annotation issues for a couple queries Example: Query 1 Results

vt3:4 --> vt3:7vt3:1 --> vt3:4vt3:0 --> vt3:1pas2:http://relation.org/softmean --> vt3:0myg1:urn:www.mygrid.org.uk/process#reslice1 --> pas2:http://relation.org/softmeanmyg1:urn:www.mygrid.org.uk/process#reslice2 --> pas2:http://relation.org/softmeanmyg1:urn:www.mygrid.org.uk/process#reslice3 --> pas2:http://relation.org/softmeanmyg1:urn:www.mygrid.org.uk/process#reslice4 --> pas2:http://relation.org/softmeanmyg1:urn:www.mygrid.org.uk/process#align_warp1 --> myg1:urn:www.mygrid.org.uk/process#reslice1myg1:urn:www.mygrid.org.uk/process#align_warp2 --> myg1:urn:www.mygrid.org.uk/process#reslice2myg1:urn:www.mygrid.org.uk/process#align_warp3 --> myg1:urn:www.mygrid.org.uk/process#reslice3myg1:urn:www.mygrid.org.uk/process#align_warp4 --> myg1:urn:www.mygrid.org.uk/process#reslice4


are needed to see this picture.Provenance API Integration Developed VisTrails Provenance Query

Language for first challenge Plan to integrate API with query

language Plan to integrate query language with

VisTrails interfaces


are needed to see this picture.Interoperability Issues Uniquely identifying intermediate results Intermediate file names were not

specified and varied Tracing ids is difficult for users–this

should be transparent A common query language should use

concepts familiar to users Mediator vs. Warehousing approach


are needed to see this picture.Performance Issues Redundant information can make queries

inefficient What is the best storage backend?

RDBMS vs. XML database? What is the best data model?

XML vs. Relational vs. RDF? Need good benchmarks–large data!


are needed to see this picture.Questions?


are needed to see this picture.Mediated ProvenanceUser queries

General Provenance Model

wrapperwrapper wrapper

Taverna

Mappingfrom genericprovenance

modelinto the models of

different systems

Pasoa …

Prov API


are needed to see this picture.Mediator ArchitectureUser SQL/ODBC queries

Mediator

Global Schema

wrapperwrapper wrapper

DataSource

Mappingfrom global

schemainto sourceschemas

DataSource

DataSource

VisTrails

Documents

provenance modelexamples

modelwrap provenance

specific data product

specific information

workflow versions

workflow structure

data miningworkflows

powerful workflow systems