CONCURRENCY AND COMPUTATION: PRACTICE AND EXPERIENCE Concurrency Computat.: Pract. Exper. (2013) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/cpe.3171 SPECIAL ISSUE PAPER AutoSLAM – A policy-based framework for automated SLA establishment in cloud environments M. Baruwal Chhetri * ,† , Q. Bao. Vo and R. Kowalczyk Faculty of Information & Communication Technologies, Swinburne University of Technology, Melbourne, Australia SUMMARY Cloud computing offers a realization of SOA in which IT resources are dynamically provisioned as services to consumers using flexible provisioning and pricing models. When provisioning such services, providers and consumers must first agree over the service usage terms and conditions, which are captured in Service Level Agreements (SLAs). In this paper, we propose a policy-based framework with corresponding mod- els, mechanisms and tools for the automated establishment of SLAs in open, diverse and dynamic cloud environments. The Automated SLA Management framework allows entities to specify their requirements and capabilities, and preferences over them in a flexible and expressive manner. It also supports multiple interaction models for SLA establishment, giving consumers and providers the flexibility to select the one that is most appropriate in a given context, while simultaneously participating in multiple concurrent SLA interactions using different interaction models. As part of the framework, we define a formal model for the underlying policies, a corresponding physical model WS-SLAM that extends WS-Policy and a reference architecture that can be easily implemented. We validate the practicability of our framework through the Smart CloudPurchaser prototype that can automatically purchase computing resources from Amazon EC2 under different scenarios and contexts. Copyright © 2013 John Wiley & Sons, Ltd. Received 15 October 2012; Revised 19 July 2013; Accepted 17 September 2013 KEY WORDS: policy-based automation; automated SLA establishment; cloud computing; preference policy; interaction policy; strategy policy 1. INTRODUCTION Cloud computing offers a realization of SOA in which IT resources can be dynamically provisioned as services to consumers using flexible provisioning and pricing models. When consuming or pro- viding such services, entities establish Service Level Agreements (SLAs) with their counterparts. These SLAs, include, among other things, the usage terms and conditions for the provisioned ser- vice. These usage terms and conditions are a key differentiator in an increasingly competitive cloud services market, which is characterized by its diversity and dynamism. Diversity results from con- sumers and providers having varying requirements, preferences and constraints over the service usage terms and conditions. Dynamism arises from varying supply and demand of the computing resources. Given the diversity and dynamism, using a static set of preferences and a single interac- tion model for SLA establishment is not appropriate in all scenarios and contexts. Service consumers and providers can benefit if they have flexible and expressive preference models and support mul- tiple interaction models and decision-making strategies for SLA establishment, so that they can dynamically adapt to changing scenarios and contexts. *Correspondence to: M. Baruwal Chhetri, Faculty of Information & Communication Technologies, Swinburne University of Technology, John Street, Hawthorn, VIC 3122, Australia. † E-mail: mchhetri@swin.edu.au Copyright © 2013 John Wiley & Sons, Ltd.