An Introduction to OSLC and Linked Data
OSLC: Lifecycle integration inspired by the web
Objectives and Pre-requisites
Objectives:

You will gain an understanding of the OSLC community,
linked data, and the OSLC specifications
– OSLC = Open Services for Lifecycle Collaboration
Pre-requisites:

none
Recommended reading:
1. http://www.linkeddatatools.com/introducing-rdf
2. http://3roundstones.com/linked-data-101/linkeddata-tutorial/
2
What’s next
The OSLC community
Linked data and RDF
An example
The OSLC specifications
3
The Integration Problem
Point-to-point
Integrations
don’t scale
Monocultures
lock you in
Maintenance, management,
and change costs go up over time
Ongoing and unexpected
costs drain resources
End-user productivity suffers:
Either stuck with the wrong tool,
stuck doing manual integration;
often stuck doing both
Creating new
integrations is
unpredictable
Past choices
restrict present
action and
future vision
Integrations consume more of the IT budget:
integration failures are the top 2 causes
of software project delays*
More limited ability to respond to change
Constrained by exhausted IT budget and lower productivity
4
* Commissioned study conducted by
Forrester Consulting on behalf of IBM.
OSLC and Open Community: open collaboration, better integration
Identify
Scenarios
Call it a
specification
Iterate on
working
drafts
Gain technical
consensus,
http://open-services.net
5
The Basics: What is OSLC, and why should I care?
OSLC is an open community building practical
specifications for integrating software
Tool Maker
• create software using reusable and open assets that will interoperate
with other tools both inside and outside your influence providing time
and cost savings
Tool
Manager
• reduce the complexity and risk of increasingly complex software
infrastructures, and improve the value of software across a broader
set of internal and external stakeholders
Tool User
• choose the best tools for your job and have them interact seamlessly
to achieve traceability and visibility with the rest of your organization
Systems
Integrator
• focus energy and resources on higher-value customizations, deliver
more business value to your clients, and increase client satisfaction
OSLC is beneficial to many stakeholders
6
OSLC’s Simple Solution
Users can work seamlessly across their tools
Architecture of the Web
Standard Interfaces
Automation
Linked Data
“Just Enough” integration
Increased reuse
Increased traceability
Monitoring
Decreased maintenance costs
Better visibility
OSLC is an open and scalable approach to lifecycle integration.
It simplifies key integration scenarios across heterogeneous tools
7
OSLC’s Big Picture
Tests, Libraries, Samples, Examples,
Reference Implementations
The Resource
for OSLC
Implementers
LINKED DATA PLATFORM WORKING GROUP
Open Services for Lifecycle Collaboration
Lifecycle integration inspired by the web
Scenario-driven &
Solution-oriented
Leading choice for
strategic integration
technology
OSLC:
8
Generally applicable: specs available for many
domains covering ALM, DevOps, ISM, and PLM
Inspired by the web
Free to use and share
Changing the industry
Proven
Open
Innovative
Eclipse Lyo
Eclipse project created with the goal of providing tools to
enable adoption of OSLC specifications.
Content includes
 Code libraries (Java, Perl, others under development)
– Give developers tools to ease OSLC implementations
 Reference implementations of specifications
– Provide a starting point for new integrations
 Test suites and test reporting. Covers OSLC Core, CM, QM, RM
and Asset today.
– Accelerate and assess development
 Samples, tutorials and documentation
– Working samples of OSLC integrations with Bugzilla, Excel,
Jazz tools and more.
http://eclipse.org/lyo
9
What’s next
The OSLC community
Linked data and RDF
An example
The OSLC specifications
10
OSLC turns data into...
Requirements
Validation Tests
Design
Implementation
R1
D1
I1
R2
D2
I2
Tool C
Tool D
T1
T2
Tool A
11
Tool B
...connected information...
Requirements
Validation Tests
Design
Implementation
T1
validates
validates
R1
satisfy
satisfy
R2
D1
D2
implements
implements
I1
I2
validates
validates
T2
Tool A
Tool B
Does every requirement
have a test to validate it?
12
Tool C
Tool D
Which requirements for
the UI are related to test
cases that failed on their
last run?
...that can facilitate applied knowledge
Requirements
Validation Tests
Design
Implementation
User Interface
T1
validates
validates
R1
satisfy
D1
I1
implements
Release
satisfy
R2
D2
T2
Tool B
Why is the number of
failed test cases for the UI
increasing in each
iteration?
13
I2
validates
validates
Tool A
implements
Processing Engine
Tool C
Tool D
How much faster is work
progressing on the UI
versus the Processing
Engine?
OSLC links lifecycle data
14
Linked Data and RDF
Tim Berners-Lee’s four principles for linking data:
1. Use URIs as names for things
2. Use HTTP URIs so that people can look up those names
3. When someone looks up a URI, provide useful information
using the standards (RDF, SPARQL)
4. Include links to other URIs so that they can discover more
things
“Instead of defining a new data model, OSLC’s resource and
property-value approach is based on industry standard
Resource Description Framework (RDF) data model.”
Adapted from: http://open-services.net/bin/view/Main/ OslcCoreSpecification
15
RDF Concepts
OSLC applies some RDF key concepts:
1. Graph data model
2. URI-based vocabulary
3. Format - Serialization syntaxes (RDF/XML, Turtle,
JSON)
4. Datatypes
5. Literals
6. Expression of simple facts
7. Entailment
We’ll briefly look at some of them.
16
1. OSLC uses an RDF graph data model
Subject
Amanda
Test Case 1
Predicate
owns
validates
Object
Car
Requirement 1
The predicate provides the property or relationship
between the subject and object.
Adapted from:
http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#section-data-model
17
2. OSLC uses a URI-based vocabulary
When there is a need to identify anything in OSLC,
use a URI (there are a few exceptions).
Using URIs allows everything to be linked together. It
also allows common agreed-upon meaning for
relationships and for resource types
<http://...Test Case 1>
<http://...validates>
<http://...Requirement 1>
OSLC Core URI Naming Guidance:
http://open-services.net/wiki/core/OSLC-Core-URI-Naming-Guidance/
18
3. OSLC allows different RDF formats
The RDF model provides for describing RDF triples.
There are various supported formats. Some are
specialized for RDF (Turtle) and others are derived
from existing formats (XML, JSON). These formats
can be exchanged between different applications
(tools).
OSLC allows different types of format:
 RDF/XML
 Turtle
 JSON
OSLC Core Specification:
http://open-services.net/bin/view/Main/OslcCoreSpecification
19
Examples of different OSLC notations
Subject
<http://...Test Case 1>
Predicate
<http://...validates>
Object
<http://...Requirement 1>
<http://example.com/TestCases/1> a oslc_qm:TestCase ;
oslc_qm:validatesRequirement <http://example.com/Requirements/1>
Turtle
{
"rdf:about": "http:\/\/example.com\/TestCases\/1",
"rdf:type": [ {
"rdf:resource": "http:\/\/open-services.net\/ns\/qm#TestPlan"
} ],
JSON
"oslc_qm:validatesRequirement": {
"rdf:resource": "http:\/\/example.com\/Requirements\/1"
}
}
<oslc_qm:TestCase rdf:about="http://example.com/TestCases/1">
<oslc_qm:validatesRequirement rdf:resource="http://example.com/Requirements/1"/>
</oslc_qm:TestCase>
20
RDF/XML
What’s next
The OSLC community
Linked data and RDF
An example
The OSLC specifications
This example is adapted from http://3roundstones.com/linkeddata-101/linked-data-tutorial/ [David Wood, 3RoundStonesInc.
November2011]
21
Here’s a fictional project
Existing product: Lunar
Rover 3.0
New Release: Lunar
Rover 3.1
Main goal is to improve
remote steering
Release to orbit date:
September 20, 2014
22
Let’s look at the requirements domain
Requirement 28465 Improve Remote
Steering
owner
Bob
release
Lunar Rover 3.1
priority
High
owned by
Iris
created on
November 24,
2011
state
23
release to
orbit date
September 20,
2014
Implemented
The same information as before, in tabular form
Requirement
Owner
Priority
Created on
State
Release
Requirement 28464
Add rear FIDO mast
Linda
Low
October 18,
2012
New
Lunar Rover
3.1
Requirement 28465
Improve Remote
Steering
Bob
High
November 24,
2011
Implemented
Lunar Rover
3.1
Requirement 28466
Rebuild wheels for soil
excavation
Tanuj
Medium
September 9,
2012
Reviewed
Lunar Rover
3.1
24
Rover Release
Owned by
Release to orbit
date
Lunar Rover 3.0
Cheng
August 16, 2011
Lunar Rover 3.1
Iris
Sept 14, 2014
Let’s look at the quality domain
Test Case 35645: Test Steering
owner
Janet
release
Lunar Rover 3.1
priority
High
owned by
Iris
created on
December 7,
2011
September 20,
2014
state
Executed
result
25
release to
orbit date
pass
Let’s add more relationships
validated by
Test Case 35645: Test
Steering
release
Requirement 28465
Improve Remote Steering
owner
owner
priority
release
Bob
Lunar Rover
3.1
High
owner
priority
created on
Iris
Janet
High
December
7, 2011
created on
November 24,
2011
state
26
Implemented
release to
orbit date
state
September
20, 2014
result
Executed
pass
The same information as before, in tabular form
Requirement
Owner
Priority
Created
on
State
Release
Validated by
Requirement
28464 Add rear
FIDO mast
Linda
Low
October 18,
2012
New
Lunar
Rover 3.1
Requirement
28465 Improve
Remote Steering
Bob
High
November
24, 2011
Implemented
Lunar
Rover 3.1
Test Case
35645: Test
Steering
Requirement
28466 Rebuild
wheels for soil
excavation
Tanuj
Medium
September
9, 2012
Reviewed
Lunar
Rover 3.1
Lunar Rover 3.1
Rover
Release
Owner
Release to
orbit date
Test Case
Owner
Priority
...
Lunar
Rover 3.0
Cheng
August 16, 2011
Test Case 35645 Test
Steering
Janet
High
...
Lunar
Rover 3.1
Iris
Sept 14, 2014
Lunar Rover 3.1
Iris
27
...
RDF triple (subject-predicate-object)
Triple
Subject = Resource
= always a URI
Requirement
28465 Improve
Remote Steering
Predicate =
Relationship or
property = Always a
URI
validated by
priority
28
Object = Could be a
URI (which could refer
to a resource) or a
literal value (value to
work with and show
users)
Test Case
35645: Test
Steering
High
RDF triple (subject-predicate-object)
Triple
Subject = Resource
= always a URI
Predicate =
Relationship or
property = Always a
URI
<http://...require
ment28465_
improve_remote
steering>
<http://...validatedby>
<http://...priority>
29
Object = Could be a
URI (which could refer
to a resource) or a
literal value (value to
work with and show
users)
<http://...testcas
e35645_test_ste
ering>
“High”
Let’s add more relationships
Work Item
38759
implements
validated by
release
Test Case 35645: Test
Steering
Requirement 28465
Improve Remote Steering
owner
owner
Janet
release
Bob
Lunar Rover 3.1
priority
High
priority
High
owner
created on
December
7, 2011
Iris
created on
November 24,
2011
state
30
Implemented
release to
orbit date
state
Executed
September
20, 2014
result
pass
There is a web of URIs around a development effort
<http://.../build>
<http://.../testresult
>
<http://.../change
request>
<http://.../build>
<http://.../test
case>
<http://.../req>
<http://.../build>
<http://.../testresult
>
<http://.../workitem
>
<http://.../test
case>
<http://.../bug>
<http://.../workitem
>
<http://.../bug>
<http://.../test
case>
<http://.../change
request>
<http://.../req>
<http://.../build>
<http://.../workitem
>
<http://.../req>
<http://.../release>
<http://.../build>
<http://.../bug>
validate
<http://.../build>
<http://.../workitem
>
<http://.../req>
<http://.../change
request>
<http://.../workitem
>
<http://.../test
case>
<http://.../req>
<http://.../testresult
>
<http://.../test
case>
<http://.../change
request>
<http://.../testresult
>
<http://.../change
request>
31
<http://.../build>
<http://.../change
request>
<http://.../testresult
>
OSLC principles
Tim Berners-Lee’s four principles applied to OSLC:

Use URIs as names for things
– In OSLC, each artifact in the lifecycle (for example, requirements,
change requests, test cases...) is identified by a URI.
 Use HTTP URIs so that people can look up those names.
– In OSLC, each artifact in the lifecycle is an HTTP resource.
Standard HTTP methods (GET, PUT, POST, DELETE) are used to
interact with them.
 When someone looks up a URI, provide useful information using the
standards (RDF*, SPARQL)
– Each OSLC resource has an RDF representation. OSLC resources
can be queried using SPARQL.
 Include links to other URIs so that they can discover more things.
– OSLC lifecycle artifacts are linked by relationships (for example,
validatesRequirement or testedByTestCase) which are defined by
URIs.
32
What’s next
The OSLC community
Linked data and RDF
An example
The OSLC specifications
33
Anatomy of a specification
OSLC Core Specification
How
What
OSLC Change Mgt
Specification
OSLC Requirements
Specification
OSLC Domain X
Specification
Core: Specifies the primary integration
techniques for integrating lifecycle tools
– the standard rules and patterns for
using HTTP and RDF that all the domain
workgroups must adopt in their
specifications
Domain: Defines integration scenarios
for a given lifecycle topic and specifies a
common vocabulary for the lifecycle
artifacts needed to support the
scenarios.
Example: The Core specification
describes Delegated UIs and Creation
Factories and states that OSLC service
providers MAY provide them. The
Change Management specification
states that CM service providers MUST
provide them.
http://open-services.net/bin/view/Main/OslcCoreSpecification
34
OSLC defines the following technical areas:
1. Discovery of
capabilities
6. UI Previews for
Resource Links
5. Delegated UI for
Create and Select
35
2. HTTP C.R.U.D. for
resources
3. Standard resource
representations
4. Querying for
resources
First, some terminology (before we get to #1)
OSLC Service
Provider catalog
provides
OSLC Service
Provider
provides an
implementation of
OSLC Service
These catalogs are used in the discovery of
OSLC service providers. They help to simplify
the configuration of tools that will integrate with
providers of OSLC-defined services.
example: IBM Rational Team
Concert
A product or online service offering that
provides an implementation of one or more
OSLC Services, which may themselves
implement different OSLC Domain
specifications
Set of capabilities that enable a web client to
create, retrieve, update and delete resources
managed by an ALM or PLM product or online
service offering and associated with one OSLC
Domain
manages
OSLC Resource
36
Managed by an OSLC Service, may have
properties and may link to other resources
including those provided by other OSLC
Services.
example: IBM Rational Team
Concert project area
example: Change Management
capability
example: work item (bug,
defect, enhancement request)
1. Discovery of capabilities
Starting from the catalog you
can discover services and their
capabilities. This is a common
pattern in OSLC.
OSLC capabilities:
Delegated UI Dialog allows you to
create or find resources using a UI
provided by the OSLC tool
Creation Factory allows you to
create resources programmatically
Query Capability allows you to
query for resources
37
2. HTTP C.R.U.D
OSLC allows manipulation of resources using standard
HTTP C.R.U.D
Create = POST
Request = GET
Update = PUT
Delete = DELETE
38
Resource Creation (Create)
Create a resource using HTTP POST, with the resource body in format
of choice
 URI for doing the POST is defined in the oslc:ServiceProvider in
the oslc:creationFactory service
Response is a 201-Created with Location HTTP header indicating
URI for resource
Request may be rejected for any number of reasons




Insufficient permissions
Missing required values
Invalid data choices
...and … and ...
Valid resource formats for creation are defined by:
 domain specifications
 service provider may define its own resources and formats
 optionally, by resource shape associated with creation factory
39
Resource Retrieval (Request)
Use HTTP GET and standard HTTP content negotiation
 Client uses HTTP Accept request header to specify desired resource formats
Accept: application/json, application/xml
Use standard content(MIME) types
Partial representations can be requested via HTTP URL key=value pair as
?oslc.properties=
 Allows for minimal retrieval of properties
 Get Defect 123 (all properties)
GET http://bugs/123
 Get Defect 123 (just title and status)
GET http://bugs/123?oslc.properties=dcterms:title,oslc_cm:status
40
Resource Modification (Update)
Use HTTP GET to get resource properties to be updated
 You’ll get an ETag back
Change only the property values you need to change
 Clients must preserve unknown content
Use HTTP PUT to send updated resource
 Use If-Match HTTP request header with ETag, services may reject
your request without it
 HTTP PUT will completely replace the resource representation
 We are moving towards PATCH – new HTTP verb
http://tools.ietf.org/html/rfc5789
It is possible to update only selected properties
41
Resource Deletion (Delete)
Use HTTP DELETE on the resource identifier
May not be allowed
Response usually:
•
•
•
•
42
200-OK
204-No-Content
400-Bad-Request
403-Forbidden
3. Resource representations
OSLC services should handle any type of resource
 Not just those defined by OSLC
Resources defined by OSLC use RDF data model
 therefore are simply defined by their set of properties
OSLC services MUST produce and consume RDF/XML
representations
 Clients and services MUST NOT assume any subset of RDF/XML
Other representations are allowed such as:
 XML: OSLC defined format that allows for consistent formats and is
RDF/XML valid
 JSON: Rules for representing namespaces and QName properties
 Turtle: No constraints, use as is (may be preferred by future specs)
 Atom Syndication Format: <atom:content> SHOULD be RDF/XML
43
A few words on Resource Linking
Links are properties where the property values are
URIs
Turtle format for a bug resource (abbreviated)
<http://example.com/bugs/2314>
a oslc_cm:ChangeRequest ;
dcterms:relation
<http://server/app/bugs/1235> ;
Don't make assumptions about the target of links
OSLC supports an open model
Needed to achieve goal of “loosely coupled” integrations
Clients need to be flexible and expect anything
Sometimes we need to provide additional data about
links: label, owners, and so on.
Special cases where links need more representation
44
4. Querying for resources
Query capability has base URI
Clients form query URI and HTTP GET the results
OSLC services MAY support OSLC Query Syntax
 http://open-services.net/bin/view/Main/OSLCCoreSpecQuery
45
Query syntax overview
Filter results by appending “oslc.where=” with query clause to query base URI

Only boolean operation allowed is “and” which represents conjunction
 “or” for disjunction is not defined in the interests of keeping the syntax simple.

Retrieve just what you want with “oslc.select=”
Defined ordering using “oslc.orderBy=”
Full-text search via “oslc.searchTerms=”



'in' operator:
Test for equality to any of the
values in a list. The list is a
comma-separated sequence
of values, enclosed in square
brackets: in [“high”,”critical”]
46
Comparison Operators
= test for equality
!= test for inequality
< test less-than
> test greater-than
<= test less-than or equal
>= test greater-than or equal
Query syntax example
Find high severity bugs created after April fools day
http://example.com/bugs?oslc.where=
cm:severity="high" and dcterms:created>"2010-04-01"
Find bugs related to test case 31459
http://example.com/bugs?oslc.prefix=qm=
<http://qm.example.com/ns>&
oslc.where=qm:testcase=<http://example.com/tests/31459>
Find all bugs created by John Smith
http://example.com/bugs?oslc.where=
dcterms:creator{
foaf:givenName="John" and foaf:familyName="Smith"}
47
5. Delegated UI renders the source app UI in the target app
A delegated UI renders the source
application UI in the target application. This
example shows the contributed/delegated
Rational Team Concert Work Item search
dialog being rendered in an OSLC Quality
Management application.
2. iframe's src
set to delegated
UI's URL
1. Click to
launch
delegated UI
4. Click OK.
Sends message
(link+label) to
parent window
48
3. Selection
made
Delegated UI key points
Delegated UIs support both creation and selection of resources
Two communication protocols are supported for iframes:
 HTML5 postMessage() ← preferred method
– Supported in most modern browers
 Window object's window.name
– Supported in older browsers and Eclipse embedded web widget
 Consumer selects which protocol to use, informs provider via fragment
identifier
Tremendous value for resource creation
 Traditionally most service logic was communicated to client and new
dialog built
 Now the rules for creation and dialog change as needed
Prefilling of creation dialog done by “creating” a dialog resource
 HTTP POST of resource format to creation dialog URL, response is URL
of dialog prefilled
49
6. UI Preview
Scenario supported: hover over link to get in context preview of resource
Simple resource format defined and retrieved using HTTP content
negotiation
Hover over link
50
OSLC specifications also include
 Common property and resource definitions covering
 Resource shapes
 Resource typical properties: title, description, identification, …
 Leveraging Dublin Core and FOAF
 Discussion/comments
 OSLC services MAY offer OAuth 1.0a
 Three legged OAuth for webapp to webapp authentication
 Two legged OAuth for client to webapp authentication
 OSLC services MAY offer HTTP BASIC Auth
 User name and password sent “in the clear” with Base64 encoding
 Should be done via HTTPS only
51
OSLC Specifications Cover Many Domains
Core & Common
•
Core, Configuration Management, Reporting
Application Lifecycle Management (ALM)
•
Change Management, Quality Management, Requirements
Management, Asset Management, Architecture
Management, Automation
(Software) Project Management
•
Estimation and Reporting
Product Lifecycle Management (PLM)
•
ALM-PLM Interoperability
Integrated Service Management (ISM)
•
52
Performance Monitoring, Reconciliation
Get Connected with OSLC
 Learn more at
 http://open-services.net
 http://eclipse.org/lyo
 Get started with your OSLC “Hello World!” with
Eclipse Lyo and existing specs
 Join the community and contribute scenarios
 Jump in and create specifications that matter to
you
Open Services for Lifecycle Collaboration
Lifecycle integration inspired by the web
53
Resources
OSLC Web Site
 http://open-services.net
OSLC Primer
 http://open-services.net/primer
OSLC Tutorial
 http://open-services.net/tutorial
OSLC Core and Domain specifications
 http://open-services.net/specifications/
Eclipse Lyo
 http://www.eclipse.org/lyo/
Even more OSLC resources
 http://open-services.net/resources/
54
BACKUP
55
Need better integration approaches
Past integration approaches have provided limited choice and coverage.
Single repository
Point-to-point integrations
“Can I really expect one vendor
to provide all the functionality I
need? And what about my
existing tools?”
“How can I ever upgrade one
tool without breaking
everything else?”
Past integration approaches have been disruptive and slow to emerge.
Universal metadata standard
Standard implementations
“How did I ever think all those
vendors would be able to
agree?”
“Did I really believe that every
vendor would rewrite their
tools on a single framework?”
56
Need open collaboration on solutions
Past collaborations have fallen short because of limited and
restrictive participation.
Limited to small set of business partners

No open process for others to join in
Limits solution to particular use cases
and technologies

Solution design goals and approach
No consensus driven approach
No external review


57
No visibility into solution
Point-to-point integrations
Built after the fact with limited
product APIs
Solution focuses on two tools in
hand

Restrictive licenses and intellectual property
License fees
Fear of giving up IP


Forces alternative solutions
OSLC community
Wide range of
interests,
expertise,
participation
Growing list of
implementations
Vendors, end users, industry consortia
40+ organizations have had employees participate in
specification development efforts
100s of developers have used assets from Lyo
Collaborating on solutions for ALM, DevOps, ISM, PLM
 Implementations from IBM Rational, Oracle, IBM Tivoli
and open source
3rd party adapters from IBM, Kovair, Tasktop, and open
source
Dozens of end users enabling homegrown tools
Specifications for
many domains
Change Management, Quality Management,
Requirements Management, Asset Management,
Architecture Management, Automation
Product Lifecycle Management, Configuration
Management
Performance Monitoring, Reconciliation
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