3 research outputs found
Proactive management of SLA violations by capturing relevant external events in a Cloud of Things environment
The cloud of things (CoT) is an emerging paradigm that has merged and combined cloud computing and the Internet of Things (IoT). Such a paradigm has enabled service providers to provide on-demand computing resources from devices spread across different locations for service users to be dynamically connected to them. While this benefits the CoT service providers and users in many ways, it also brings a key challenge of ensuring that the service is delivered according to the promised quality. Failure to ensure this will result in the service provider experiencing penalties of different types and the service user experiencing disruptions. The literature addresses this problem by proactively managing for SLA violations. However, given the geographically dispersed region of a formed CoT service, in this paper we argue that for proactive SLA violation identification, we need specialized techniques that also consider events that are outside the usual control of service providers and users, but will impact the CoT environment and the quality of service. We propose a framework that identifies such external events of interest and ascertains their impact on achieving the service according to the promised quality. We explain the working of our proposed framework in detail and demonstrate its superiority in proactively determining SLA violations as compared to existing approaches
Service level agreement specification for IoT application workflow activity deployment, configuration and monitoring
PhD ThesisCurrently, we see the use of the Internet of Things (IoT) within various domains
such as healthcare, smart homes, smart cars, smart-x applications, and smart
cities. The number of applications based on IoT and cloud computing is projected
to increase rapidly over the next few years. IoT-based services must meet
the guaranteed levels of quality of service (QoS) to match users’ expectations.
Ensuring QoS through specifying the QoS constraints using service level agreements
(SLAs) is crucial. Also because of the potentially highly complex nature
of multi-layered IoT applications, lifecycle management (deployment, dynamic
reconfiguration, and monitoring) needs to be automated. To achieve this it is
essential to be able to specify SLAs in a machine-readable format.
currently available SLA specification languages are unable to accommodate
the unique characteristics (interdependency of its multi-layers) of the IoT domain.
Therefore, in this research, we propose a grammar for a syntactical structure
of an SLA specification for IoT. The grammar is based on a proposed conceptual
model that considers the main concepts that can be used to express the requirements
for most common hardware and software components of an IoT application
on an end-to-end basis. We follow the Goal Question Metric (GQM) approach to
evaluate the generality and expressiveness of the proposed grammar by reviewing
its concepts and their predefined lists of vocabularies against two use-cases
with a number of participants whose research interests are mainly related to IoT.
The results of the analysis show that the proposed grammar achieved 91.70% of
its generality goal and 93.43% of its expressiveness goal.
To enhance the process of specifying SLA terms, We then developed a toolkit
for creating SLA specifications for IoT applications. The toolkit is used to simplify
the process of capturing the requirements of IoT applications. We demonstrate
the effectiveness of the toolkit using a remote health monitoring service (RHMS)
use-case as well as applying a user experience measure to evaluate the tool by
applying a questionnaire-oriented approach. We discussed the applicability of our
tool by including it as a core component of two different applications: 1) a contextaware
recommender system for IoT configuration across layers; and 2) a tool for
automatically translating an SLA from JSON to a smart contract, deploying it
on different peer nodes that represent the contractual parties. The smart contract
is able to monitor the created SLA using Blockchain technology. These two
applications are utilized within our proposed SLA management framework for IoT.
Furthermore, we propose a greedy heuristic algorithm to decentralize workflow
activities of an IoT application across Edge and Cloud resources to enhance
response time, cost, energy consumption and network usage. We evaluated the
efficiency of our proposed approach using iFogSim simulator. The performance
analysis shows that the proposed algorithm minimized cost, execution time, networking,
and Cloud energy consumption compared to Cloud-only and edge-ward
placement approaches