sla template filtering: a faceted approach

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

Thank you!

April 12, 2023Institute of Services Science (ISS)

Q&A: aikaterini.stamou@unige.ch

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.