Slides of the presentation for my PhD dissertation. I strongly recommend downloading the slides, as they have animations that are easier to see in power point. The abstract of the thesis is as follows: "Scientific workflows have been adopted in the last decade to represent the computational methods used in in silico scientific experiments and their associated research products. Scientific workflows have demonstrated to be useful for sharing and reproducing scientific experiments, allowing scientists to visualize, debug and save time when re-executing previous work. However, scientific workflows may be difficult to understand and reuse. The large amount of available workflows in repositories, together with their heterogeneity and lack of documentation and usage examples may become an obstacle for a scientist aiming to reuse the work from other scientists. Furthermore, given that it is often possible to implement a method using different algorithms or techniques, seemingly disparate workflows may be related at a higher level of abstraction, based on their common functionality. In this thesis we address the issue of reusability and abstraction by exploring how workflows relate to one another in a workflow repository, mining abstractions that may be helpful for workflow reuse. In order to do so, we propose a simple model for representing and relating workflows and their executions, we analyze the typical common abstractions that can be found in workflow repositories, we explore the current practices of users regarding workflow reuse and we describe a method for discovering useful abstractions for workflows based on existing graph mining techniques. Our results expose the common abstractions and practices of users in terms of workflow reuse, and show how our proposed abstractions have potential to become useful for users designing new workflows".
PhD Thesis: Mining abstractions in scientific workflows
1. Date: 03/12/2015
Mining Abstractions in
Scientific Workflows
Daniel Garijo *
Supervisors: Oscar Corcho *, Yolanda Gil Ŧ
* Universidad Politécnica de Madrid,
Ŧ USC Information Sciences Institute
3. Benefits of workflows
Time savings
•Copy & paste fragments of workflows
3PhD Thesis: Mining Abstractions in Scientific Workflows
Teaching
•Reduce the learning curve of new students
Visualization
•Simplify workflows
Design for modularity
•Highlight the most relevant steps on a workflow
Design for standardization
Debugging
•Provenance exploration
Reproducibility and inspectability
4. Motivation of this work
Workflow Repositories
Workflow Systems
Let’s
Share!
I want to
reuse…
?
I want to
understand…?
I want to
repurpose…
?
4PhD Thesis: Mining Abstractions in Scientific Workflows
5. Open research challenges
•Workflow representation heterogeneity
5PhD Thesis: Mining Abstractions in Scientific Workflows
Workflow Repositories
How can we represent a description of workflows and their metadata?
How can we facilitate the homogeneous consumption of workflows and
their resources?
6. Open research challenges
•Workflow representation heterogeneity
6PhD Thesis: Mining Abstractions in Scientific Workflows
•Inadequate level of workflow abstraction
What are the most relevant
parts of a workflow
Dataset
Porter
Stemmer
Result
IDF
Final
Result
Dataset
Lovins
Stemmer
Result
Residual
IDF
Final
Result
Dataset
Stemmer
Result
Term Weighting
FinalResult
Are two seemingly disparate
workflows related at a
higher level of abstraction?
7. Open research challenges
•Workflow representation heterogeneity
7PhD Thesis: Mining Abstractions in Scientific Workflows
•Inadequate level of workflow abstraction
•Difficulties for workflow reuse
How is a workflow related to
other workflows?
Which workflow (parts) are
potentially useful for reuse?
?
?
?
8. Open research challenges
•Workflow representation heterogeneity
8PhD Thesis: Mining Abstractions in Scientific Workflows
•Inadequate level of workflow abstraction
•Difficulties for workflow reuse
•Lack of support for workflow annotation
+ +
How can we facilitate the annotation process?
9. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph mining techniques
6. Evaluation
7. Conclusions and future work
9PhD Thesis: Mining Abstractions in Scientific Workflows
10. •H.3: Commonly occurring patterns are potentially useful for users
designing workflows.
•H.2: It is possible to detect commonly occurring patterns and
abstractions automatically.
Hypothesis
•H.1: It is possible to define a catalog of common domain
independent patterns based on the common functionality of
workflow steps.
Scientific workflow repositories can be automatically analyzed to
extract commonly occurring patterns and abstractions that are
useful for workflow developers aiming to reuse existing workflows.
Workflow abstraction
Workflow representation
Workflow reuse
Workflow annotation
Workflow reuse
10PhD Thesis: Mining Abstractions in Scientific Workflows
11. Contributions
Workflow representation and publication
Model for representing workflow templates and executions
Workflow abstraction
Methodology to publish workflows in the web
Workflow annotation
A model and means for annotating semi-automatically the abstractions in
workflows
A catalog of common domain independent workflow patterns based on the
functionality of workflow steps
A method to extract generic commonly occurring workflow fragments
automatically
Workflow reuse
Metrics for assessing the usefulness of a fragment for reuse
A model to describe and annotate workflow fragments
11PhD Thesis: Mining Abstractions in Scientific Workflows
OPMW
Linked Data
Wf-motifs
Wf-fd
Workflow
motifs
Graph mining
12. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
a) Requirements
b) The OPMW model
c) Publishing workflows as Linked Data
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph mining techniques
6. Evaluation
7. Conclusions and future work
12PhD Thesis: Mining Abstractions in Scientific Workflows
14. Requirements
14PhD Thesis: Mining Abstractions in Scientific Workflows
Workflow template description
Plan: P-Plan [Garijo et al 2012]
http://purl.org/net/p-plan
Workflow execution trace description
Provenance: PROV (W3C) [Lebo et al 2013]
http://www.w3.org/ns/prov#
Workflow attribution
Dublin Core, PROV (W3C)
Workflow metadata
Link between templates and executions
Scufl DAX
AGWL Dispel
IWIR
OPM
OBI EXPO ISA
PAV
RO D-PROV
[Cicarese et al 2013]
[Moreau et al 2011]
[Brinkman et al 2010]
[Soldatova and King
2006]
[Rocca et al 2008]
[Belhajjame et al 2012]
[Missier et al 2013]
[Oinn et al 2004]
[Fahringer et al 2005]
[Atkinson et al 2013]
[Plankensteiner et al
2005]
16. Outline
1. Introduction and motivation
2. Hypothesis and work methodology
3. Workflow representation: OPMW
a) Requirements
b) The OPMW model
c) Publishing workflows as Linked Data
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph mining techniques
6. Evaluation
7. Conclusions and future work
16PhD Thesis: Mining Abstractions in Scientific Workflows
17. Publishing workflows as Linked Data
Specification
17PhD Thesis: Mining Abstractions in Scientific Workflows
Why Linked Data?
•Facilitates exploitation of workflow resources in an homogeneous manner
Adapted methodology from [Villazón-Terrazas et al 2011]
Tested it for the Wings workflow system
1
Base URI = http://www.opmw.org/
Ontology URI = http://www.opmw.org/ontology/
Assertion URI = http://www.opmw.org/export/resource/ClassName/instanceName
Examples:
http://www.opmw.org/export/resource/WorkflowTemplate/ABSTRACTSUBWFDOCKING
http://www.opmw.org/export/resource/WorkflowExecutionAccount/ACCOUNT1348629
350796
18. Publishing workflows as Linked Data
Specification Modeling
18PhD Thesis: Mining Abstractions in Scientific Workflows
Why Linked Data?
•Facilitates exploitation of workflow resources in an homogeneous manner
Adapted methodology from [Villazón-Terrazas et al 2011]
Tested it for the Wings workflow system
1 2
OPMW
P-Plan
OPM DC
PROV
19. Publishing workflows as Linked Data
Specification Modeling Generation
19PhD Thesis: Mining Abstractions in Scientific Workflows
Why Linked Data?
•Facilitates exploitation of workflow resources in an homogeneous manner
Adapted methodology from [Villazón-Terrazas et al 2011]
Tested it for the Wings workflow system
1 2 3
Workflow system
Workflow
Template
Workflow
execution
OPMW
export
OPMW
RDF
20. Publishing workflows as Linked Data
Specification Modeling Generation Publication
20PhD Thesis: Mining Abstractions in Scientific Workflows
Why Linked Data?
•Facilitates exploitation of workflow resources in an homogeneous manner
Adapted methodology from [Villazón-Terrazas et al 2011]
Tested it for the Wings workflow system
1 2 3 4
RDF
Triple
store
Permanent
web-
accessible
file
store
RDF Upload Interface
SPARQL
Endpoint
OPMW
RDF
21. Publishing workflows as Linked Data
Specification Modeling Generation Publication
21PhD Thesis: Mining Abstractions in Scientific Workflows
Why Linked Data?
•Facilitates exploitation of workflow resources in an homogeneous manner
Adapted methodology from [Villazón-Terrazas et al 2011]
Tested it for the Wings workflow system
1 2 3 4
Exploitation
5
Curl Linked Data Browser
Workflow
Explorer
SPARQL
endpoint
22. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
a) A catalog of common workflow abstractions
b) Workflow reuse analysis
5. Mining abstractions from workflows using graph mining techniques
6. Evaluation
7. Conclusions and future work
22PhD Thesis: Mining Abstractions in Scientific Workflows
23. A catalog of common workflow abstractions
Generalization of workflow steps based on functionality.
Workflow motif: Domain independent conceptual abstraction on the workflow
steps.
1. Data-oriented motifs: What kind of manipulations
does the workflow have?
•E.g.:
•Data retrieval
•Data preparation
•Data curation
•Data visualization
• etc.
23PhD Thesis: Mining Abstractions in Scientific Workflows
24. A catalog of common workflow abstractions
Generalization of workflow steps based on functionality.
Workflow motif: Domain independent conceptual abstraction on the workflow
steps.
1. Data-oriented motifs: What kind of manipulations
does the workflow have?
•E.g.:
•Data retrieval
•Data preparation
• etc.
2. Workflow-oriented motifs: How does
the workflow perform its operations?
•E.g.:
•Stateful steps
•Stateless steps
•Human interactions
•etc.
24PhD Thesis: Mining Abstractions in Scientific Workflows
25. Methodology for finding workflow motifs
Goal: Reverse-engineer the set of current practices in workflow
development through an analysis of empirical evidence
25PhD Thesis: Mining Abstractions in Scientific Workflows
= 260 workflows
89 12526 20
Collect workflows
26. Methodology for finding workflow motifs
Goal: Reverse-engineer the set of current practices in workflow
development through an analysis of empirical evidence
26PhD Thesis: Mining Abstractions in Scientific Workflows
Preliminary workflow analysis
Researcher 1 Researcher 2 Researcher 3
27. Methodology for finding workflow motifs
Goal: Reverse-engineer the set of current practices in workflow
development through an analysis of empirical evidence
27PhD Thesis: Mining Abstractions in Scientific Workflows
Agreement and cross validation
28. Result Summary
28PhD Thesis: Mining Abstractions in Scientific Workflows
•Over 60% of the motifs are data preparation motifs
•Some differences are motivated by the workflow systems in the
analysis
•Around 40% of workflows contain motifs related to workflow
reuse
composite workflowsinternal macros
But how do users perceive workflow reuse?
What about fragments of workflows?
29. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
a) A catalog of common workflow abstractions
b) Workflow reuse survey
5. Mining abstractions from workflows using graph mining techniques
6. Evaluation
7. Conclusions and future work
29PhD Thesis: Mining Abstractions in Scientific Workflows
30. Use case: The LONI Pipeline
Workflow system for neuroimaging analysis
http://pipeline.loni.usc.edu/explore/library-navigator/
30PhD Thesis: Mining Abstractions in Scientific Workflows
Discussions with scientists
User survey
Collect responses
from users
21 responses
Discuss results
31. Summary results
The majority of users agree that reusing and sharing workflows is
useful
Unlike workflows, reusing groupings from one’s own work is more
useful than reusing groupings from others
Most respondents agreed that groupings help simplify workflows.
Groupings also make workflows more understandable by others
31PhD Thesis: Mining Abstractions in Scientific Workflows
Can we detect groupings automatically?
32. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph
mining techniques
a) Corpus preparation
b) Graph mining
c) Fragment filtering
d) Fragment linking
6. Evaluation
7. Conclusions and future work
32PhD Thesis: Mining Abstractions in Scientific Workflows
33. Workflow mining approaches
Clustering [Montani and Leonardi 2012] , [García-Jimenez and Wilkinson, 2014]
33PhD Thesis: Mining Abstractions in Scientific Workflows
Workflow corpus
Cluster1
Cluster 2
Cluster 3
Workflow corpus
34. Workflow mining approaches
Clustering [Montani and Leonardi 2012] , [García-Jimenez and Wilkinson, 2014]
34PhD Thesis: Mining Abstractions in Scientific Workflows
Topic 1
Topic 2
P(Topic1) = 0.7
P(Topic2)= 0.3
P(Topic1) = 0.5
P(Topic2)= 0.5
P(Topic1) = 0.2
P(Topic2)= 0.8 ….
Topic modeling [Stoyanovich et al 2010]
35. Workflow mining approaches
Clustering [Montani and Leonardi 2012] , [García-Jimenez and Wilkinson, 2014]
Topic modeling [Stoyanovich et al 2010]
35PhD Thesis: Mining Abstractions in Scientific Workflows
Case-based reasoning [Leake and Kendall-Morwick 2008], [Müller and Bergmann 2014]
Workflow corpus
?
36. ?
Workflow mining approaches
Clustering [Montani and Leonardi 2012] , [García-Jimenez and Wilkinson, 2014]
Topic modeling [Stoyanovich et al 2010]
Case-based reasoning [Leake and Kendall-Morwick 2008] [Müller and Bergmann 2014]
Log mining [van del Aalst et al2003] [Gómez-Pérez and Corcho, 2008]
36PhD Thesis: Mining Abstractions in Scientific Workflows
Workflow corpus
?
PSM
37. Workflow mining approaches
Clustering [Montani and Leonardi 2012] , [García-Jimenez and Wilkinson, 2014]
Topic modeling [Stoyanovich et al 2010]
Case-based reasoning [Leake and Kendall-Morwick 2008] [Müller and Bergmann 2014]
Log mining [van del Aalst et al2003] [Gómez-Pérez and Corcho, 2008]
Graph mining [Diamantini et al., 2012]
37PhD Thesis: Mining Abstractions in Scientific Workflows
38. Workflow Mining in FragFlow
1
2
3
4
38PhD Thesis: Mining Abstractions in Scientific Workflows
39. Corpus Preparation
Workflows converted to Labeled Directed Acyclic Graphs (LDAG)
• The label of a node in the graph corresponds to the type of the step in
the workflow
• Edges capture the dependencies between different steps
39PhD Thesis: Mining Abstractions in Scientific Workflows
Dataset
Stemmer
algorithm
Result
Term weighting
algorithm
FinalResult
Stemmer
algorithm
Term weighting
algorithm
Duplicated workflows are removed
Single-step workflows are removed
40. Graph Mining
We use popular graph mining techniques:
Inexact FSM: usage of heuristics to calculate similarity between two
graphs. The solution might not be complete
SUBDUE
2 heuristics: Minimum Description Length (MDL) and Size
Exact FSM: deliver all the possible fragments to be found the dataset.
gSpan
Depth first search strategy
FSG
Breadth first search strategy
40PhD Thesis: Mining Abstractions in Scientific Workflows
41. Filtering Relevant Fragments
The number of resulting fragments can be very large. We distinguish:
Multistep fragments:
More than one step
Filtered Multistep fragments:
Multistep fragments
Contain all smaller fragments with the same number of occurrences
41PhD Thesis: Mining Abstractions in Scientific Workflows
Stemmer
Term Weighting
Stemmer
Term Weighting
Filter
Filter
Sort
Filter
Sort
Query
F1
F2
F3
F4
(found 4 times)
(found 4 times)
(found 10 times)
(found 3 times)
42. Linking to the Corpus: Example
Workflow 1
42PhD Thesis: Mining Abstractions in Scientific Workflows
Stemmer
Term Weighting
Stemmer
Term Weighting
Merge
Stemmer
Term Weighting
Fragment1in Wf1(1)
Fragment1
Fragment1in Wf1(2)
Workflow fragment description vocabulary:
http://purl.org/net/wf-fd
(Extends P-Plan)
wffd:foundAs
wffd:foundAs
wffd:foundIn
p-plan:isPrecededBy
p-plan:isPrecededByp-plan:isPrecededBy
p-plan:isPrecededBy p-plan:isPrecededBy p-plan:isStepOfPlan
p-plan:isStepOfPlan
p-plan:isStepOfPlan
p-plan:isStepOfPlan
p-plan:isStepOfPlan
p-plan:Step
wffd:TiedWorkflowFragment
wffd:DetectedResultWorkflowFragment
43. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph
mining techniques
6. Evaluation
a) Finding generic motifs in workflows
b) Workflow fragment assessment
7. Conclusions and future work
43PhD Thesis: Mining Abstractions in Scientific Workflows
44. Finding generic motifs in workflows
44PhD Thesis: Mining Abstractions in Scientific Workflows
?
Research question: Can we find commonly occurring abstractions?
composite workflowsinternal macros
45. Finding generic motifs in workflows
45PhD Thesis: Mining Abstractions in Scientific Workflows
?
Metrics used: precision and recall
Fragments
(F)
Annotated
motifs
(M)
46. Finding generic motifs in workflows
46PhD Thesis: Mining Abstractions in Scientific Workflows
?
Corpus: 22 templates from the same domain annotated manually
Wings workflow corpus + domain knowledge
Dataset
Porter
Stemmer
Result
IDF
Final
Result
Dataset
Lovins
Stemmer
Result
Residual
IDF
Final
Result
+
Dataset
Stemmer
Result
Term Weighting
FinalResult
Stemmer
Porter Stemmer
Lovins Stemmer
Term Weighting
Inverse Document
Frequency (IDF)
Residual IDF
Query Term Weighting
Component taxonomy
47. Finding generic motifs in workflows
47PhD Thesis: Mining Abstractions in Scientific Workflows
?
Results of the evaluation
H.2: It is possible to detect commonly occurring patterns and abstractions
automatically.
Internal Macros:
Inexact FSM : 2 out of 3 found (r=0,67); 4 out of 5 (r=0,8) when applying
generalization
Composite Workflows:
Exact FSM: all motifs are found, although the precision is low (p=0,18)
Can we find commonly occurring abstractions?
48. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph
mining techniques
6. Evaluation
a) Finding generic motifs in workflows
b) Workflow fragment assessment
7. Conclusions and future work
48PhD Thesis: Mining Abstractions in Scientific Workflows
49. Workflow fragment assessment
49PhD Thesis: Mining Abstractions in Scientific Workflows
?
Research question: Are our proposed workflow fragments useful?
•A fragment is useful if it has been designed and (re)used by a user.
•Comparison between proposed fragments and user designed groupings
and workflow
50. Workflow fragment assessment
50PhD Thesis: Mining Abstractions in Scientific Workflows
?
Metrics: Precision and recall
Fragments
(F)
Workflows
(W)
Groupings
(G)
51. Workflow fragment assessment
51PhD Thesis: Mining Abstractions in Scientific Workflows
?
Workflow corpora
User Corpus 1 (WC1)
• Designed mostly by a single a single user
• 790 workflows (475 after data preparation)
User Corpus 2 (WC2)
• Created by a user, with collaborations of others
• 113 workflows (96 after data preparation)
Multi User Corpus 3 (WC3)
• Workflows submitted by 62 users during the month of Jan 2014
• 5859 workflows (357 after data preparation)
User Corpus 4 (WC4)
• Designed mostly by a single a single user
• 53 workflows (50 after data preparation)
52. Workflow fragment assessment
52PhD Thesis: Mining Abstractions in Scientific Workflows
?
Result assessment
•30%-60% of proposed fragments are equal to user defined groupings or
workflows
•40%-80% of proposed of proposed fragments are equal or similar to user
defined groupings or workflows
H.3: Commonly occurring patterns are potentially useful for users designing workflows
What about the rest of the fragments? Are those useful?
53. Workflow fragment assessment
53PhD Thesis: Mining Abstractions in Scientific Workflows
?
User feedback: user survey
Q1: Would you consider the proposed fragment a valuable grouping?
•I would not select it as a grouping (0)
•I would use it as a grouping with major changes (i.e., adding/removing more than 30% of the steps) (1)
•I would use it as a grouping with minor changes (i.e., adding/removing less than 30% of the steps) (2).
•I would use it as a grouping as it is (3)
Q2: What do you think about the complexity of the fragment?
•The fragment is too simple (0)
•The fragment is fine as it is (1)
•The fragment has too many steps (2)
Not enough evidence to state that all proposed workflow fragments are useful
54. Outline
1. Introduction and motivation
2. Hypothesis and contributions
3. Workflow representation: Open Provenance Model for Workflows
4. Workflow abstraction and reuse
5. Mining abstractions from workflows using graph
mining techniques
6. Evaluation
7. Conclusions and future work
54PhD Thesis: Mining Abstractions in Scientific Workflows
55. Conclusions: Results
H.1: It is possible to define a catalog of common domain independent patterns based on
the common functionality of workflow steps.
Daniel Garijo and Yolanda Gil. A new approach for publishing workflows: Abstractions, standards, and Linked Data. (WORKS'11)
Daniel Garijo, Pinar Alper, Khalid Belhajjame, Oscar Corcho, Yolanda Gil, Carole Goble. Common motifs in scientific workflows: An empirical analysis (extended
version). Future Generation Computer Systems. 2013.
Model for representing workflows (OPMW) and publishing them as Linked Data
Catalog of workflow motifs + workflow annotation
H.2: It is possible to detect commonly occurring patterns and abstractions automatically.
Graph mining approach + workflow generalization
Daniel Garijo, Pinar Alper, Khalid Belhajjame, Oscar Corcho, Yolanda Gil, Carole Goble. Common motifs in scientific workflows: An empirical analysis. 8th IEEE
International Conference on e-Science (eScience 2012)
55PhD Thesis: Mining Abstractions in Scientific Workflows
Daniel Garijo, Oscar Corcho and Yolanda Gil. Detecting common scientific workflow fragments using templates and execution provenance. Proceedings of the
seventh international conference on Knowledge capture, (K-CAP 2013).
56. Conclusions: Results
Daniel Garijo, Oscar Corcho, Yolanda Gil, Boris Gutman, Ivo D. Dinov, Paul Thompson and Arthur W. Toga. FragFlow: Automated fragment detection in
scientific workflows. 10th IEEE Conference on e-Science, (eScience 2014)
Daniel Garijo, Oscar Corcho, Yolanda Gil, Meredith N. Braskie, Dereck Hibar, Xie Hua, Neda Jahanshad, Paul Thompson and Arthur W. Toga. Workflow reuse in
practice: A study of neuroimaging pipeline users. 10th IEEE Conference on e-Science, (eScience 2014)
H.3: Commonly occurring patterns are potentially useful for users designing workflows.
Graph mining approach + reusability metrics for assessment + workflow annotation
56PhD Thesis: Mining Abstractions in Scientific Workflows
Reuse survey
57. Conclusions: Impact and future work
Impact:
OPMW
•Workflow annotation [García-Jiménez and Wilkinson 2014b]
Motif catalog
•Expansion for distributed environments [Olabarriaga et al 2013]
•Workflow summarization [Alper et al 2013]
Future work:
•Towards workflow ecosystems
57PhD Thesis: Mining Abstractions in Scientific Workflows
[Garijo et al 2014] (WORKS’14)
58. Conclusions: Impact and future work
•Automatic detection of workflow abstractions
58PhD Thesis: Mining Abstractions in Scientific Workflows
•Improvement of workflow reuse
Custom fragments
Ranking fragments
Suggestions of workflows
59. Date: 03/12/2015
Mining Abstractions in
Scientific Workflows
Daniel Garijo *
Supervisors: Oscar Corcho *, Yolanda Gil Ŧ
* Universidad Politécnica de Madrid,
Ŧ USC Information Sciences Institute
All materials are available as Research Objects
(with pointers to Figshare)
http://w3id.org/dgarijo/ro/mining-abstractions-in-scientific-wfs
61. Methodology
Workflow representation and publication
Approach
Workflow abstraction and reuse
Empirical
analysis of
workflow
corpora
Problem Evaluation
Requirement
validation and
user feedback
Model Competency
question
validation
Provenance
Plan
Publication
Methodology
for publication
Extension of
existing
standards
and web
technologies
Workflow
abstraction
analysis for
reuse
Agreement on
a catalog of
common
abstractions
Automatic detection and annotation of
workflow abstractions
Graph mining
techniques,
generalization
Precision,
recall and user
feedback
61PhD Thesis: Mining Abstractions in Scientific Workflows
62. Provenance Models
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid 62
“A record that describes the people, institutions, entities, and activities
involved in producing, influencing, or delivering a piece of data or a thing”
-PROV-DM: The PROV Data Model (W3C)
63. Replace this slide with a methodological one
prov:used
p-plan:Variable
p-plan:isStepOfPlan
p-plan:isVariableOfPlan
p-plan:hasInputVar
p-plan:isOutputVarOf
p-plan:Activity
p-plan: correspondsToStep
p-plan:Entity
prov:wasGeneratedBy
p-plan:isPrecededBy
p-plan:Bundle
Class Object property
Legend
Subclass of
prov:Bundle
prov:Plan
prov:Entity
prov:Activity
PROVextendedclasses
Statements contained in a p-plan:Bundle
p-plan:Step
p-plan:Plan
p-plan: correspondsToVariable
63PhD Thesis: Mining Abstractions in Scientific Workflows
64. Assumptions and restrictions
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid 64
Restriction:
• Workflows are represented as directed acyclic graphs
Assumptions:
•Available workflow repositories exist for exploiting definitions
of workflows and workflow executions.
•All the workflow steps can be assigned a label with their type
•Two steps of a workflow with the same function have the
same type.
•Researchers aim to reuse workflows and workflow fragments
if they find them useful.
65. 9
Other models for representing workflow instances, templates and executions
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
66. Publishing as LD
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid 66
•Maybe paste here an example
instead of the big picture
67. 67
Data Oriented Motifs
Data-Oriented Motifs
Data Retrieval
Data Preparation
Format Transformation
Input Augmentation
and Output Splitting
Data Organisation
Data Analysis
Data Curation/Cleaning
Data Movement
Data Visualisation
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
68. 68
Data Oriented Motifs
Data-Oriented Motifs
Data Retrieval
Data Preparation
Format Transformation
Input Augmentation
and Output Splitting
Data Organisation
Data Analysis
Data Curation/Cleaning
Data Movement
Data Visualisation
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
69. 69
Data Oriented Motifs
Data-Oriented Motifs
Data Retrieval
Data Preparation
Format Transformation
Input Augmentation
and Output Splitting
Data Organisation
Data Analysis
Data Curation/Cleaning
Data Movement
Data Visualisation
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
70. 70
Data Oriented Motifs
Data-Oriented Motifs
Data Retrieval
Data Preparation
Format Transformation
Input Augmentation
and Output Splitting
Data Organisation
Data Analysis
Data Curation/Cleaning
Data Movement
Data Visualisation
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
71. 71
Data Oriented Motifs
Data-Oriented Motifs
Data Retrieval
Data Preparation
Format Transformation
Input Augmentation
and Output Splitting
Data Organisation
Data Analysis
Data Curation/Cleaning
Data Movement
Data Visualisation
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
72. 72
Data Oriented Motifs
Data-Oriented Motifs
Data Retrieval
Data Preparation
Format Transformation
Input Augmentation
and Output Splitting
Data Organisation
Data Analysis
Data Curation/Cleaning
Data Movement
Data Visualisation
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
78. Result Summary: Data Oriented Motifs
•Over 60% of the motifs are data
preparation motifs
•Some differences are motivated by the
workflow systems in the analysis
•Data analysis is often the main
functionality of the workflow
78PhD Thesis: Mining Abstractions in Scientific Workflows
79. Result Summary: Workflow Oriented Motifs
• Around 40% composite workflows and internal macros
But how do users perceive workflow reuse?
•What about fragments of workflows?
79PhD Thesis: Mining Abstractions in Scientific Workflows
80. 80
Differences and commonalities of the workflow systems
•Data moving/retrieval, stateful interactions and human interaction steps are
not present in Wings
•Web services (Taverna) versus software components (Wings)
•Wings has layered execution through Pegasus
•Data preparation steps are common in both systems
•Use of sub workflows is high
PhD Thesis: Mining Abstractions in Scientific Workflows- Madrid
81. Reusing workflows…
According to the respondents, the major benefits of workflows include:
• Time savings
•Organizing and storing code
• Having a visualization of the overall analysis
• Facilitating reproducibility
81PhD Thesis: Mining Abstractions in Scientific Workflows
82. Reusing groupings…
•Reuse is not the only reason why groupings are created. Unlike workflows, reusing
groupings from one’s own work is more useful than reusing groupings from others
•Most respondents agreed that groupings help simplify workflows. Groupings also
make workflows more understandable by others
82PhD Thesis: Mining Abstractions in Scientific Workflows
83. Graph Mining
We use popular graph mining techniques:
Inexact FSM: usage of heuristics to calculate similarity between two
graphs. The solution might not be complete
SUBDUE
• 2 heuristics: Minimum Description Length (MDL) and Size
• Frequency based
Exact FSM: deliver all the possible fragments to be found the dataset.
gSpan
• Depth first search strategy
• Support based
FSG
• Breadth first search strategy
• Support based
83PhD Thesis: Mining Abstractions in Scientific Workflows
84. Linking to the Corpus: Workflow fragment description vocabulary
84PhD Thesis: Mining Abstractions in Scientific Workflows
86. Conclusions: Limitations
L1: OPMW has been designed for data-intensive workflows (without loops or
conditionals)
L2: When publishing as Linked Data, it is assumed that all resources will be made public
(no privacy issues)
L3: Motif catalog may be expanded with additional motifs
L4: Size and time needed to calculate some workflow fragments
L5: A taxonomy of components is needed when generalizing workflows. This taxonomy is
provided by domain experts modeling the domain.
86PhD Thesis: Mining Abstractions in Scientific Workflows
Notas del editor
Data driven, usually represented as Directed Acyclic Graphs (DAGs)
These are the points discussed with scientists, not the results of the user survey.
Sharing workflows with collaborators: Non-programmers find a barrier to running complex neuroimaging analyses as they cannot create components or code to that level of complexity. Reusing workflows that others have created enable them to do tasks that they would not otherwise do.
Teaching: Breakpoints are often placed throughout the pipeline to serve as checkpoints and make sure that execution was performed correctly
Visualization: The hierarchical organization can be used to group functionally related tasks into a single visual element. This allows workflow developers to group complex tasks with highly-fragmented code into a single visual unit that other users can incorporate into their workflows
Modularity: Workflows provide a high-level view of the major steps involved in an analysis, and exposing those major steps drives the design of the code in a modular fashion
Representation: different types of workflows use different types of representation. Also, we miss the links to the resources associated to the workflow itself.
Reuse: workflow reused as part of other workflows. How?
Abstractions: are two seemingly disparate workflows related to each other?
Workflow template and instance: steps and their dependencies
Workflow execution trace: provenance of the results
Experiment metadata: specific methods, author contribution, etc.
P-Plan is simple and extensible (to cater to cases that require more complex wf operators)
Say that P-Plan has been used for describing scientific processes in social sciences and lab protocols
State that the focus is workflow description
Example of motif goes here on each side, instead of the big HOW and WHAT
In order to improve understandability, we have decided as a first step to identify what are the common operations in scientific workflows, by doing an empirical analysis over different domains.
There is existing work on this, but mainly tackles the structure of the workflow rather than the operation that is going on.
Thus, our approach has been to start without any initial definitions of motifs to find. Instead we have reverse-engineered the different steps in the workflows trying to create clusters with the most common motifs.
Example of motif goes here on each side, instead of the big HOW and WHAT
In order to improve understandability, we have decided as a first step to identify what are the common operations in scientific workflows, by doing an empirical analysis over different domains.
There is existing work on this, but mainly tackles the structure of the workflow rather than the operation that is going on.
Thus, our approach has been to start without any initial definitions of motifs to find. Instead we have reverse-engineered the different steps in the workflows trying to create clusters with the most common motifs.
Corpus collection
Preliminary analysis of workflows
Discuss catalog of motifs
Find motifs in workflows
Cross validate annotations
Discussion until agreement
Corpus collection
Preliminary analysis of workflows
Discuss catalog of motifs
Find motifs in workflows
Cross validate annotations
Discussion until agreement
Corpus collection
Preliminary analysis of workflows
Discuss catalog of motifs
Find motifs in workflows
Cross validate annotations
Discussion until agreement
Workflow reuse. It is very important not because we say so, but because we have seen it in many of the workflows.
In almost 40% of the workflows include some other workflow. And when it doesn’t, it is very similar in many cases
(we have just matched the exact available workflows)
Internal macros, for instance, show how different parts of workflows repeat, which could lead to new workflow templates as well.
Explain some of the features of LONI. Grey circles are inputs, triangles outputs and blue circles components. The rectangles in dots are groupings.
Explain what a grouping is, and what is it for.
In general, workflows are considered generally more useful than groupings. On the other hand, more respondents said that groupings help make their code more modular and understandable
Can we automatically mine a repository of workflows to derive useful workflow fragments?
State that graph mining has only been tested recently
Clustering and topic modeling: good for stating similar workflows, but not necessarily mining common workflow fragments
Log mining: good for suggesting next steps, but bad for stating relationships among workflows
Case based reasoning: it is used for prediction mostly
State that graph mining has only been tested recently
Clustering and topic modeling: good for stating similar workflows, but not necessarily mining common workflow fragments
Log mining: good for suggesting next steps, but bad for stating relationships among workflows
Case based reasoning: it is used for prediction mostly
State that graph mining has only been tested recently
Clustering and topic modeling: good for stating similar workflows, but not necessarily mining common workflow fragments
Log mining: good for suggesting next steps, but bad for stating relationships among workflows
Case based reasoning: it is used for prediction mostly
State that graph mining has only been tested recently
Clustering and topic modeling: good for stating similar workflows, but not necessarily mining common workflow fragments
Log mining: good for suggesting next steps, but bad for stating relationships among workflows
Case based reasoning: it is used for prediction mostly
State that graph mining has only been tested recently
Clustering and topic modeling: good for stating similar workflows, but not necessarily mining common workflow fragments
Log mining: good for suggesting next steps, but bad for stating relationships among workflows
Case based reasoning: it is used for prediction mostly
Overview of the steps here. Say clearly that
Here explain what it means to capture a dependency between 2 steps: that a data product produced by the former is consumed by the latter.
Duplicated workflows are removed because if we have like 500 workflows that are the same, what we are going to find is that the common fragments are those repeated workflows themselves.
Explain in detail support based versus frequency based techniques!
Explain DFS versus BFR strategies! (don’t go into too much detail).
The number of fragments can be up to millions when the common parts are of size >10.
Mention that this is done by issuing sparql queries to link the fragments like the one in the figure to the corpus
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
High Recall-> expected value
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
State the expected value!! (High precision)
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
This indicates that our fragments are commonly occurring and generic. It also indicated that the rest of the fragments could be useful for users.
Wf ecosystems: most of the work is towards making wfs executable on other places, but forgetting about all the other apps that use and consume the wfs at different granularities.
Wf abstractions: being able to generate a domain taxonomy automatically. Detecting automatically some of the rest of the motifs.
Improvement of workflow reuse: by proposing rankings, improving the interfaces and in general exploiting directly all the data that we can discover with the thesis proposed here.
Wf ecosystems: most of the work is towards making wfs executable on other places, but forgetting about all the other apps that use and consume the wfs at different granularities.
Wf abstractions: being able to generate a domain taxonomy automatically. Detecting automatically some of the rest of the motifs.
Improvement of workflow reuse: by proposing rankings, improving the interfaces and in general exploiting directly all the data that we can discover with the thesis proposed here.
Genomics workflow - Using Biomart and EMBOSS services, This workflow retrieves a number of sequences from 3 species: mouse, human, rat; aligns them through multiple sequence alignment, and returns a plot of the alignment result. Corresponding sequence ids are also returned.
Heliophysics workflow (we counted t as astronomy) - This is a fragment of a workflow that uses several input augmentation motifs in order to create a query to be sent to the Helio Feature Catalog service to retrieve the active regions on the solar surface for a given period of time
Describe briefly each of the data oriented motifs
This workflow calculates QSAR (Quantitative structure–activity relationship) properties of a compound and saves them as a CSV file. The molecules are read iteratively from an SDF file. Additionally it writes out the molecules with unknown atom types, salt counter ions, curated molecule library with UUIDs and the used calculation time of every QSAR descriptor as a CSV file.Furthermore explicit hydrogens are added and a Hueckel aromaticity detection is performed
Cheminformatics workflow - It curates the structural information regarding a compound that is provided in Structure Data Format (SDF) file format. This workflow generates atom signatures for individual compounds given the SDF file as input
Describe briefly each of the data oriented motifs
This workflow performs an NCBI blast at the EBI. It uses the new EBI services, which are asynchronous and require multiple invocations - repeatedly invoking the getStatus sub-workflow until the blast job is complete. So the blast is actually undertaken by 3 callls RUN+GET_STATUS+GET_RESULT
Explain briefly the workflow oriented motifs:
Scientific workflows Msc course workflow - This workflow fetches the details of the countries in the world and then uses R to produce a histogram of the log of their population
Explain briefly the workflow oriented motifs:
Text-Analytics workflow- it is used for reading natural language text found within files with specified extensions in the specified directory
The first fact that we discovered about the workflows is that over 60% of the motifs in each domain are data preparation motifs.
In fact, most of them are Input augmentation, output spliting and reformatting steps are the most common in most workflows.
This is very important because it tells us how many intermediate processing steps are in the workflow. These steps are often notrelevant for explaining the functionality of the workflow.
Another relevant thing to show is that between 10-15% of the motifs are data analysis. This is very important, since this is often the main step
Of the workflow, its main functionality. If there is only a 15%, it means that the workflow could have been much smaller.
Workflow reuse. It is very important not because we say so, but because we have seen it in many of the workflows.
In almost 40% of the workflows include some other workflow. And when it doesn’t, it is very similar in many cases
(we have just matched the exact available workflows)
Internal macros, for instance, show how different parts of workflows repeat, which could lead to new workflow templates as well.
What we also noticed with this analysis is that this 2 workflow systems are essentially very similar.
They share all the motifs except for data moving/retrieval, since Wings uses Pegasus and its infrastructure for that;
Stateful interactions (since Wings is oriented to use scripts and tools rather than web services), and human interaction steps.
We noticed during the analysis that the typing of data often helps for avoiding certain intermediate steps.
Workflow reuse is high in both systems, as we stated previously
In general, workflows are considered generally more useful than groupings. On the other hand, more respondents said that groupings help make their code more modular and understandable
Explain in detail support based versus frequency based techniques!
Explain DFS versus BFR strategies! (don’t go into too much detail).
For the goal 1, we have to say that we also relaxed the first precision and recall to an 80 percent to see if similar fragments were found as well.
For the Goal 3, there is nothing to quantify.