1. The GEMBus Architecture and Core Components
Diego Lopez, RedIRIS

2. Connected in Heterogeneity
GEMBus is a middleware layer to support service integration according to SOA principles in a multi-domain environment
Inspired on the ESB paradigm
Free application services from common concerns
Security, discovery, message management, ...
Go beyond the single central authority in current ESB systems
Taking a step further into federated infrastructures
Independent management
Metadata as backbone

3. The Three Principles
Build a flexible infrastructure able to accommodate existing service frameworks
Loosely-coupled “bus of buses”
Impose the fewest additional requirements on services
Basic mediation services to ease integration
Set the ground for simplifying lifecycle and interactions
Supporting service management frameworks

4. Bus of Buses
Based on a registry with a semantically rich internal format
Service ontology
Suitable for different frameworks and design styles

5. Minimum Requirements Limit requirements to basic aspects
Message routing and traceability
Security token exchange protocols
Service containers and descriptions
Leave the rest as an E2E issue
GEMBus provides basic mediation services
Security (Authentication and authorization)
Accounting (Log creation and access)
Composition (Orchestration and workflow)
Other constraints/services/interfaces/… as an added value
Part of the “common bus” or even specialized buses

6. Foundation for a Service Framework
Middleware to support (and combine) service provisioning/integration frameworks
NGN Open Service Environment
TMForum/IPSphere SDF
OGSA

7. GEMBus Elements GEMBus core infrastructure
Supports service operation and provisioning
Specific software elements
Profiles on supporting service frameworks
Specific component services
Component services.
Comply with an interface (service containers)
Either atomic or composite
Deployed at any participating service framework
Can be dynamically provisioned from service repositories

8. The GEMBus Core The GEMBus Registry GMI: GEMBus Message Infrastructure
GEMSTS: GEMBus Security Token Service
GLOS: GEMBus Logging Service
Service Composition Services

9. The GEMBus Registry Service ontology based on OWL/RDF
Several service description formats
WSDL, WADL, OSGi,...
Service metadata
Semantics come into play
Complex queries and reasoning
Richer import/export mechanisms
Multiple instances
Synchronization via publish/subscribe mechanisms
Collaboration with the USDL initiative

10. GMI: GEMBus Messaging Infrastructure
Elements built by tailored standard implementations
Message processor
Aspect based interceptors and event handlers
Message routing module
A Configuration Manager providing dynamical configuration of GMI specific components
Conventions that define names and identifiers for the GEMBus endpoints, entities, elements, attributes and properties

11. GEMSTS: GEMBus Security Token Service
User authentication outside the GEMBus scope
STS split into two atomic services
TTS: AuthN (token issuance)
AS: AuthR (token validation)
Both can use external sources for
Identity: Attribute authorities
Policies: PDPs
Session tokens to reduce authorization overhead

12. GLOS: GEMBus Logging Service
A key facility for accounting, statistics, diagnostics,…
Handler integrated in the GMI
GLOS service instance at each participating framework
Common log repository/ies
Collection of interactions at the GMI level
RDF as internal format

13. Service Composition Services
Orchestration implemented by a WS-BPEL execution engine
Apache ODE is the current choice
Implementation and management environment
Eclipse plugin based on BPMN
Workflow integration into service deployment
Taverna tools
Awaiting for OSGi interface availability

14. Service Integration Patterns
Identified and exercised through actual integration of current GÉANT services

15. Core Access Patterns: Full Integration
Adapting elements relieve services from direct interaction with the core
Deployed at the bus level or in service containers

16. Core Access Patterns: Mixed Integration
Fine-grained control of core behavior through direct API calls
Opens core usage to services deployed outside GEMBus boundaries

17. GEMBus So Far Architecture defined and validated
Prototypes of (most) core elements
Registry
STS
Composition
Being discussed and evaluated by potential user communities
Soon to be integrated in an openly available portal
Demonstrator on GEMBus concepts and applicability
Implementation of an AC (Autonomous Computing) application
Come and see the demo!

18. The Task Ahead: Consolidating GEMBus
Making the core elements achieve a stable status
Service characterization
What makes a service suitable for being deployed in GEMBus
What makes it suitable for using the GEMBus Core
What is required to be included in the GEMBus Registry
What is required to be composed with other services
Service deployment mechanisms
Service repositories
Service containers
Validation, deployment and provisioning mechanisms
Documentation
Collecting experience in a GEMBus Cookbook

19. The Middleware Mantra