sla template filtering: a faceted approach
DESCRIPTION
Presentation in Valencia, Spain, 30.05.2013TRANSCRIPT
T H E F O U R T H I N T E R N AT I O N A L C O N F E R E N C E O N C L O U D C O M P U T I N G , G R I D S , A N D V I R T U A L I Z AT I O N
C L O U D C O M P U T I N G 2 0 1 3
SLA Template Filtering: A Faceted Approach
K. Stamou, V. Kantere and J.H. Morin{aikaterini.stamou, verena.kantere, jean-henry.morin}@unige.ch
April 12, 2023Institute of Services Science (ISS)
Contents
April 12, 2023Institute of Services Science (ISS)
Problem formalization
Faceted navigation
SLA template repository
Experimentation
On-going work, conclusions
SLA definition, tree-structure
April 12, 2023Institute of Services Science (ISS)
A Service Level Agreement provides an explicit view on how a service provisioning is planned
Providers and customers use SLAs to measure actual consumption of resources during service execution
SLAs represent nested tree structures
According to (Ludwig et al. 2003, Andrieux et al. 2007) a SLA consists of three primary sections:o Service description o Guarantees or obligations o An informative section regarding involved parties
and/or the provisioned service
Research challenges
April 12, 2023Institute of Services Science (ISS)
Obstacle: SLAs hardly appear in marketplaces… Equilibrium: SLAs as automated processes vs. static, non-
machine readable documents
Semantic and structural heterogeneity of SLA content, semi-structured data of unbounded length
SLA data model requirements: Modularity
Dynamic updates
Rapid traversals through branches of diverse, nested information
SLA templates
April 12, 2023Institute of Services Science (ISS)
A pre-instantiated SLA that encloses a provider’s resource availability and provisioning plan
Customers review SLA templates and proceed with either agreement initialization or negotiation with service providers
SLA templates:
Can be viewed as ”What You See Is What You Get” (WYSIWIG) snapshots
Include dynamic information that is updated at frequent time intervals
Need to ensure dynamic content updates
Content modularity allows viewing service offer sections as facets
Facets, SLA data-model
April 12, 2023Institute of Services Science (ISS)
A facet represents a category of hierarchically ordered information
SLA faceted filtering enables flexible service navigation that is driven by customer provisioning requirements
Data-model: Data categorization into distinct SLA modules
Nesting within a SLA template module depends on information content
Information granularity
SLA filtering model
April 12, 2023Institute of Services Science (ISS)
2-layered design
A template may contain up to N SLA root-themes
Parameter combinations indicate navigation and filtering options
Data modularity and model multidimensional structure allow for quick and selective navigation through designated nested information
SLA template storage
April 12, 2023Institute of Services Science (ISS)
Document-based schema (MongoDB)
Relational schema (MySQL)
Experimentation setup
April 12, 2023Institute of Services Science (ISS)
Filters in faceted navigation translate customer choices into conditional queries
Assumptions:
An IT marketplace provides SLA faceted navigation as an interaction tool for customers to submit their criteria
One centralized data repository for the SLA template storage
Simulation environment setup:
24 Intel-Xeon 2.50 GHz computing machine, 128GB of RAM, OS: Ubuntu 12.04
Web server deployment: Tornado (Python)
Client: multithreaded Python scripts pass HTTP GET requests to the web server
Both DBMS are deployed on the same machine to reduce TCP overhead
Goal: server response time to incoming customer requests and scalability of the filtering operation as the number of simultaneous requests increase
Experimentation results
April 12, 2023Institute of Services Science (ISS)
oConcurrent client requests of diverse service parameters reach the serveroIncoming parameters represent SLA facet attributes
oTest 1: total time of the filtering operation over HTTP
oTimings include HTTP and backend processing overhead
Experimentation results
April 12, 2023Institute of Services Science (ISS)
oTest 2: filtering runs are processed locally on the server to avoid additional network overheadoStart with 100 and reach up to 100,000 concurrent requests for both databases
oUpdate queries are processed in parallel to filtering requests and account for an extra 10% of workload on the total database processing
Conclusions and on-going work
April 12, 2023Institute of Services Science (ISS)
oA NoSQL approach possibly fits better for the web scenario, where SLA offers are manipulated over HTTPoCurrent work involves the SLA transformation into a dependency graph (Ward et al. 2002)
oExperimentation with regular path queries can help evaluate the pros/cons of the graph database approach
References
April 12, 2023Institute of Services Science (ISS)
Ludwig, H., Keller, A., Dan, A., King, R.P., Franck, R. 2003. "Web Service Level Agreement (WSLA) Language Specification," in: IBM Research. IBM Corporation.
Andrieux, A., Czajkowski, K., Dan, A., Keahey, K., Ludwig, H., Nakata, T., Pruyne, J., Rofrano, J., Tuecke, S., Xu, M. 2007. "Web Services Agreement Specification (WS-Agreement)." Open Grid Forum.
Ward, C., Buco, M.J., Chang, R. N., Luan, L. Z. 2002. "A Generic SLA Semantic Model for the Execution Management of E-Business Outsourcing Contracts," Proceedings of the Third International Conference on E-Commerce and Web Technologies: Springer-Verlag, pp. 363-376.