One of the challenges of deploying multitenant cloud-hosted services that are designed to use (or be integrated with) several components is how to implement the required degree of isolation between the components when there is a change in the workload. Achieving the highest degree of isolation implies deploying a component exclusively for one tenant; which leads to high resource consumption and running cost per component. A low degree of isolation allows sharing of resources which could possibly reduce cost, but with known limitations of performance and security interference. This paper presents a model-based algorithm together with four variants of a metaheuristic that can be used with it, to provide near-optimal solutions for deploying components of a cloud-hosted application in a way that guarantees multitenancy isolation. When the workload changes, the model-based algorithm solves an open multiclass QN model to determine the average number of requests that can access the components and then uses a metaheuristic to provide near-optimal solutions for deploying the components. Performance evaluation showed that the obtained solutions had low variability and percent deviation when compared to the reference/optimal solution. We also provide recommendations and best practice guidelines for deploying components in a way that guarantees the required degree of isolation.

/pdf/optimal-deployment-of-components-of-cloud-hosted-application-2s0jpq4fof.pdf

Optimal deployment of components of cloud-hosted application for guaranteeing multitenancy isolation

Security is a key challenge in the deployment and broader acceptance of cloud computing services, and existing research efforts include evaluating the effectiveness of various security solutions such as security policy implementations and technological solutions. Attacks on cloud environment may be considered from the criminological perspective, and crime theories be used to protect the cloud. This paper introduces a conceptual cloud security model utilizing the concept of situational crime prevention (SCP). Using SCP techniques, it may be possible to design process and technology-based steps to modifying the cloud computing environment to make it less attractive to crime.

Situational Crime Prevention and the Mitigation of Cloud Computing Threats

A challenge, when implementing multi-tenancy in a cloud-hosted software service, is how to ensure that the performance and resource consumption of one tenant does not adversely affect other tenants. Software designers and architects must achieve an optimal degree of tenant isolation for their chosen application requirements. The objective of this research is to reveal the trade-offs, commonalities, and differences to be considered when implementing the required degree of tenant isolation. This research uses a cross-case analysis of selected open source cloud-hosted software engineering tools to empirically evaluate varying degrees of isolation between tenants. Our research reveals five commonalities across the case studies: disk space reduction, use of locking, low cloud resource consumption, customization and use of plug-in architecture, and choice of multi-tenancy pattern. Two of these common factors compromise tenant isolation. The degree of isolation is reduced when there is no strategy to reduce disk space and customization and plug-in architecture is not adopted. In contrast, the degree of isolation improves when careful consideration is given to how to handle a high workload, locking of data and processes is used to prevent clashes between multiple tenants and selection of appropriate multi-tenancy pattern. The research also revealed five case study differences: size of generated data, cloud resource consumption, sensitivity to workload changes, the effect of the software process, client latency and bandwidth, and type of software process. The degree of isolation is impaired, in our results, by the large size of generated data, high resource consumption by certain software processes, high or fluctuating workload, low client latency, and bandwidth when transferring multiple files between repositories. Additionally, this research provides a novel explanatory framework for (i) mapping tenant isolation to different software development processes, cloud resources and layers of the cloud stack; and (ii) explaining the different trade-offs to consider affecting tenant isolation (i.e. resource sharing, the number of users/requests, customizability, the size of generated data, the scope of control of the cloud application stack and business constraints) when implementing multi-tenant cloud-hosted software services. This research suggests that software architects have to pay attention to the trade-offs, commonalities, and differences we identify to achieve their degree of tenant isolation requirements.

/pdf/degrees-of-tenant-isolation-for-cloud-hosted-software-4tog0pk1he.pdf

Degrees of tenant isolation for cloud-hosted software services: a cross-case analysis

Multi-tenant databases (MTD) are aspect of computing that has become one of the revolutionary technologies of recent years. This technology has helped to discard the large-scale investments in hardware and software resources, in upgrading them regularly and also in expensive licences of application software used on in- house hosted database systems. A MTD is a way of deploying a Database as a Service (DaaS) for the convenience and benefits of tenants. This concept is good for higher scalability and flexibility but it involves a lot of technicalities. The adoption of a MTD is based on some salient factors which can be grouped into four categories for easy understanding. A survey is presented in this research that involves a focus group of thirty respondents. The result shows the degree of impact each factor has on the decision to adopt a MTD. This paper also considers these factors and develops a framework that will help prospective tenants to take an informed decision about the adoption of the concept. Index Terms—Multi-tenant, Database as a Service, Scalability, Flexibility, Factor, Framework, Adoption.

/pdf/a-framework-for-multi-tenant-database-adoption-based-on-the-1cc172fr9b.pdf

A framework for multi-tenant database adoption based on the influencing factors

In this technology era, technology is getting change very vastly. As per the present trend in the technology cloud computing is one of the dynamic key computing and used to shared resourcefully pay for use concept in the cloud computing is much attractive and adopted by many organizational the usage of software service has been tremendously increasing that the development of different software or applications and keep available cloud user on the cloud environment. So that in this paper a new software development life cycle (SDLC) is proposed for cloud software services and is termed as CloudSDLC.

/pdf/cloudsdlc-cloud-software-development-life-cycle-1cbkitxsw9.pdf

CloudSDLC: Cloud Software Development Life Cycle

Multi-tenant applications are usually cloud based software services which can serve different users at the same time. This is done using single instance of applications by sharing hardware, infrastructure, data storage and virtualization. To achieve multi tenancy different approaches are there at every layer (Application, Data, hardware).Multi tenancy helps to minimize the effort needed for deployment and maintenance with an adequate level of security and privacy. Now a day the work is going on custom multi tenancy by sharing everything at each layer. This paper will describe the techniques of multi tenancy and how security, flexibility and scalability relate to each other when it comes to multi tenancy for customization.

/pdf/an-approach-towards-customized-multi-tenancy-359blk1v0z.pdf

Mirza Ahsan Ullah

Papers

An Approach Towards Customized Multi- Tenancy