A review of SLA specification languages in the cloud computing

Abstract

A Service Level Agreement (SLA) represents an agreement between a cloud provider and cloud customer in the context of a particular service provision. This raises the following question: How to describe the SLA terms between prospective signatories, such as service levels, Quality of Service properties, penalties in case of SLA violation, etc. SLA can be represented by specialized languages for easing SLA preparation, automating SLA negotiation, adapting services automatically according to SLA terms, and reasoning about their composition. Therefore, the aim of this work is to present a comprehensive review of how SLAs are created, managed and used in web services and cloud computing environment. This paper provides a review of SLA languages specification. Among them the WSLA, WS-Agreement, SLA*, CSLA and SLAC. Then, a comparison of these languages in terms of the requirements is presented, highlighting their strengths and weaknesses.