Tenant-centric Sub-Tenancy Architecture in Software-as-a-Service

AbstractMulti-tenancy architecture (MTA) is often used in Software-as-a-Service (SaaS) and the central idea is that multiple tenant applications can be developed using components stored in the SaaS infrastructure. Recently, MTA has been extended to allow a tenant application to have its own sub-tenants, where the tenant application acts like a SaaS infrastructure. In other words, MTA is extended to STA (Sub-Tenancy Architecture). In STA, each tenant application needs not only to develop its own functionalities, but also to prepare an infrastructure to allow its sub-tenants to develop customized applications. This paper applies Crowdsourcing as the core to STA component in the development life cycle. In addition, to discovering adequate fit tenant developers or components to help build and compose new components, dynamic and static ranking models are proposed. Furthermore, rank computation architecture is presented to deal with the case when the number of tenants and components becomes huge. Finally, experiments are performed to demonstrate that the ranking models and the rank computation architecture work as design

SDN/NFV-enabled satellite communications networks: opportunities, scenarios and challenges

In the context of next generation 5G networks, the satellite industry is clearly committed to revisit and revamp the role of satellite communications. As major drivers in the evolution of (terrestrial) fixed and mobile networks, Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies are also being positioned as central technology enablers towards improved and more flexible integration of satellite and terrestrial segments, providing satellite network further service innovation and business agility by advanced network resources management techniques. Through the analysis of scenarios and use cases, this paper provides a description of the benefits that SDN/NFV technologies can bring into satellite communications towards 5G. Three scenarios are presented and analysed to delineate different potential improvement areas pursued through the introduction of SDN/NFV technologies in the satellite ground segment domain. Within each scenario, a number of use cases are developed to gain further insight into specific capabilities and to identify the technical challenges stemming from them.Peer ReviewedPostprint (author's final draft

A coordination protocol for user-customisable cloud policy monitoring

Cloud computing will see a increasing demand for end-user customisation and personalisation of multi-tenant cloud service offerings. Combined with an identified need to address QoS and governance aspects in cloud computing, a need to provide user-customised QoS and governance policy management and monitoring as part of an SLA management infrastructure for clouds arises. We propose a user-customisable policy definition solution that can be enforced in multi-tenant cloud offerings through an automated instrumentation and monitoring technique. We in particular allow service processes that are run by cloud and SaaS providers to be made policy-aware in a transparent way

A Reference Architecture for Provisioning of Tools as a Service: Meta-Model, Ontologies and Design Elements

Abstract not availableMuhammad Aufeef Chauhan, Muhammad Ali Babar, Quan Z. Shen

Multi-tenant Pub/Sub processing for real-time data streams

Devices and sensors generate streams of data across a diversity of locations and protocols. That data usually reaches a central platform that is used to store and process the streams. Processing can be done in real time, with transformations and enrichment happening on-the-fly, but it can also happen after data is stored and organized in repositories. In the former case, stream processing technologies are required to operate on the data; in the latter batch analytics and queries are of common use. This paper introduces a runtime to dynamically construct data stream processing topologies based on user-supplied code. These dynamic topologies are built on-the-fly using a data subscription model defined by the applications that consume data. Each user-defined processing unit is called a Service Object. Every Service Object consumes input data streams and may produce output streams that others can consume. The subscription-based programing model enables multiple users to deploy their own data-processing services. The runtime does the dynamic forwarding of data and execution of Service Objects from different users. Data streams can originate in real-world devices or they can be the outputs of Service Objects. The runtime leverages Apache STORM for parallel data processing, that combined with dynamic user-code injection provides multi-tenant stream processing topologies. In this work we describe the runtime, its features and implementation details, as well as we include a performance evaluation of some of its core components.This work is partially supported by the European Research Council (ERC) un- der the EU Horizon 2020 programme (GA 639595), the Spanish Ministry of Economy, Industry and Competitivity (TIN2015-65316-P) and the Generalitat de Catalunya (2014-SGR-1051).Peer ReviewedPostprint (author's final draft

Virtual Resources & Internet of Things

Internet of Things (IoT) systems mostly follow a Cloud-centric approach. These systems get the benefits of the extensive computational capabilities and flexibility of the Cloud. Although Cloud-centric systems support virtualization of components to interact with IoT networks, many of these systems introduce high latency and restrict direct access to IoT devices. Fog computing has been presented as an alternative to reduce latency when engaging IoT networks, however, new forms of virtualization are required to access physical devices in a direct manner. This research introduces a definition of Virtual Resources to enable direct access to IoT networks and to allow richer interactions between applications and IoT components. Additionally, this work proposes Virtual Resources as a mechanism to handle the multi-tenancy challenge that emerges when more than one tenant tries to access and manipulate an IoT component simultaneously. Virtual Resources are developed using Go language and CoAP protocol. This work proposes permission-based blockchain to provision Virtual Resources directly on IoT devices. Seven experiments have been done using Raspberry Pi computers and Edison Arduino boards to test the definition of Virtual Resources presented by this work. The results of the experiments demonstrate that Virtual Resources can be deployed across different IoT platforms. Also, the results show that Virtual Resources and blockchain can support multi-tenancy in the IoT space. IBM Bluemix Blockchain as a Service and Multichain blockchain have been evaluated handling the provisioning of Virtual Resources in the IoT network. The results of these experiments show that permission-based blockchain can store the configurations of Virtual Resources and provision these configurations in the IoT network