1. Dagstuhl, February 16, 2009 Layers in Grids Uwe Schwiegelshohn 17. Februar 2009 Layers in Grids

2. Dagstuhl, February 16, 2009 Layers in Grids Internet 2 Wide Area Network ViSE Net ClientApp. User MRI/CT Distributed Computing & Gigabit Local Area Network Local User Physical apparatus Virtual-lab Information Management for Cooperation (VIMCO) Communication & collaboration (ComCol) Virtual Simulation & Exploration Environment (ViSE) Advanced Scientific Domains Computational Physics System Engineering Computational Bio-medicine Philosophical Structure of ViroLab Courtesy of Peter Sloot

3. Dagstuhl, February 16, 2009 Layers in Grids Experiment developer Scientist Clinical Virologist Experiment Planning Environment Experiment scenario ViroLab Portal Virtual Laboratory runtime components (Required to select resources and execute experiment scenarios)‏ Computational services (services (WS, WTS, WS-RF), components (MOCCA), jobs (EGEE, AHE))‏ Data services (DAS data sources, standalone databases)‏ Grids, Clusters, Computers, Network Users Interfaces Runtime Services Infrastructure Patient Treatment Support Actual Structure of ViroLab Courtesy of Marian Bubak Hardware, OS Middleware: basic services, brokerage Virtualization Community

4. Dagstuhl, February 16, 2009 Layers in Grids Services / Resources Operation Users Community/ VOs Support, Security,… PhysicsMedicineFinance Organization Layers

5. Dagstuhl, February 16, 2009 Layers in Grids Simple Structure

6. Dagstuhl, February 16, 2009 Layers in Grids Easy Replacement Version 1.3 Version 1.5

7. Dagstuhl, February 16, 2009 Layers in Grids (Double) Cone Structure

8. Dagstuhl, February 16, 2009 Layers in Grids Questions Where to use layers in Grids? –Organization, technology Relation between different layer architectures –Correspondence between a layer in organization and a layer in technology? How many layers? –As many as necessary, as few as possible Integration into existing layer structures –Software layers, organizations Assignment of tasks to layers Interface between layers Tools to support the use of layers

9. Dagstuhl, February 16, 2009 Layers in Grids Discussion Bypassing of layers see IP/TCP –No generalized requirement, see security –Distinction between implementation layers and structural layers Using attributes for distinction –Distinction between functional and non functional properties Monitoring, control and steering of non functional properties Clean structure of service provisioning –Easy replacement is not always possible: difference between internal changes and functional modifications Experience from the past in using layers –LHC: baseline services high level services: functional requirements Organizational question: responsibility Standard uses case for establishing a new community? –Generalization of virolab Different approaches: service based, component based –Collection of functions, no contradiction: a service in a layer will add something to a layer, the abstraction of a given layer can be implemented by different components.

10. Dagstuhl, February 16, 2009 Layers in Grids Discussion The classic layer approach does not work: Bottom up allocation –Alternative approach: Definition of processes and mapping of these processes to “layers” –Requirement to change the layering (layers are vehicles to master complexity) Example: issues in self * properties Layers are not implementation prescriptions, they are abstractions –Achieving of layers: Minimizing the number of interfaces (economy) “New” dimension of problems in the data domain –Annotation, similar problems occur in the commercial domain –Necessity of many levels of data and its derivation. This must be supported. Layers are about responsibility –Maturity matters: After a system is mature less layers may be necessary. Handling of failures –Mapping of failures to the organizational structures

11. Dagstuhl, February 16, 2009 Layers in Grids Discussion Communication across layers –Monitoring and tracking of the process flow across the layers as long as the flow stays within the system: system responsibility Failure handling, accounting, performance improvement, quality assurance Consistency of results with the actual data, not a new problem but a new dimension of the problem: key property of the scientific approach Service quality –Coordination of complex tasks SLA management –The top layer must understand the whole structure or each decision has to be percolated up to the top structure: multicriteria –Management structure: community specific -> example virolab Parallel support layers: machines, services support different (all) communities Network operation maps to the virolab layer picture