Using Microservices to Customize Multi-Tenant SaaS: From Intrusive to Non-Intrusive

Customization is a widely adopted practice on enterprise software applications such as Enterprise resource planning (ERP) or Customer relation management (CRM). Software vendors deploy their enterprise software product on the premises of a customer, which is then often customized for different specific needs of the customer. When enterprise applications are moving to the cloud as mutli-tenant Software-as-a-Service (SaaS), the traditional way of on-premises customization faces new challenges because a customer no longer has an exclusive control to the application. To empower businesses with specific requirements on top of the shared standard SaaS, vendors need a novel approach to support the customization on the multi-tenant SaaS. In this paper, we summarize our two approaches for customizing multi-tenant SaaS using microservices: intrusive and non-intrusive. The paper clarifies the key concepts related to the problem of multi-tenant customization, and describes a design with a reference architecture and high-level principles. We also discuss the key technical challenges and the feasible solutions to implement this architecture. Our microservice-based customization solution is promising to meet the general customization requirements, and achieves a balance between isolation, assimilation and economy of scale

Event-based Customization of Multi-tenant SaaS Using Microservices

Popular enterprise software such as ERP, CRM is now being made available on the Cloud in the multi-tenant Software as a Service (SaaS) model. The added values come from the ability of vendors to enable customer-specific business advantage for every different tenant who uses the same main enterprise software product. Software vendors need novel customization solutions for Cloud-based multi-tenant SaaS. In this paper, we present an event-based approach in a non-intrusive customization framework that can enable customization for multi-tenant SaaS and address the problem of too many API calls to the main software product. The experimental results on Microsoft’s eShopOnContainers show that our approach can empower an event bus with the ability to customize the flow of processing events, and integrate with tenant-specific microservices for customization. We have shown how our approach makes sure of tenant-isolation, which is crucial in practice for SaaS vendors. This direction can also reduce the number of API calls to the main software product, even when every tenant has different customization services.publishedVersio

Migrating Monoliths to Microservices-based Customizable Multi-tenant Cloud-native Apps

It was common that software vendors sell licenses to their clients to use software products, such as Enterprise Resource Planning, which are deployed as a monolithic entity on clients’ premises. Moreover, many clients, especially big organizations, often require software products to be customized for their specific needs before deployment on premises. While software vendors are trying to migrate their monolithic software products to Cloud-native Software-as-a-Service (SaaS), they face two big challenges that this paper aims at addressing: 1) How to migrate their exclusive monoliths to multi-tenant Cloud-native SaaS; and 2) How to enable tenant-specific customization for multi-tenant Cloud-native SaaS. This paper suggests an approach for migrating monoliths to microservice-based Cloud-native SaaS, providing customers with a flexible customization opportunity, while taking advantage of the economies of scale that the Cloud and multi-tenancy provide. Our approach shows not only the migration to microservices but also how to introduce the necessary infrastructure to support the new services and enable tenant-specific customization. We illustrate the application of our approach on migrating a reference application of Microsoft called SportStore.acceptedVersio

Hybrid Cloud Workload Monitoring as a Service

Cloud computing and cloud-based hosting has become embedded in our daily lives. It is imperative for cloud providers to make sure all services used by both enterprises and consumers have high availability and elasticity to prevent any downtime, which impacts negatively for any business. To ensure cloud infrastructures are working reliably, cloud monitoring becomes an essential need for both businesses, the provider and the consumer. This thesis project reports on the need of efficient scalable monitoring, enumerating the necessary types of metrics of interest to be collected. Current understanding of various architectures designed to collect, store and process monitoring data to provide useful insight is surveyed. The pros and cons of each architecture and when such architecture should be used, based on deployment style and strategy, is also reported in the survey. Finally, the essential characteristics of a cloud monitoring system, primarily the features they host to operationalize an efficient monitoring framework, are provided as part of this review. While its apparent that embedded and decentralized architectures are the current favorite in the industry, service-oriented architectures are gaining traction. This project aims to build a light-weight, scalable, embedded monitoring tool which collects metrics at different layers of the cloud stack and aims at achieving correlation in resource-consumption between layers. Future research can be conducted on efficient machine learning models used on the monitoring data to predict resource usage spikes pre-emptively

Network isolation for Kubernetes hard multi-tenancy

Over the past decade, containerization is increasingly popular due to its advantages in performance compared to virtualization. The rise in the use of containers leads to the emergence of container orchestration tools. Kubernetes is one of the top widely used tools serving this purpose. One critical point in the design of this tool is that one cluster can only serve one tenant. As the number of Kubernetes users is continuously increasing, this model generates considerate management overheads and resource fragmentation to the cluster. As a result, multi-tenancy was introduced as an alternative model. However, the major problem of this approach is the isolation between tenants. This thesis aims to tackle this isolation issue. While many cluster resources need to be isolated, we concentrate on handling one crucial feature in Kubernetes hard multi-tenancy: Network isolation. Our solution for this problem is intended to work regardless of the implementation flexibility of the Kubernetes network. The solution can also pass most of our security tests. The remaining issues are not significant, and one of them is solvable. Besides, our performance experiments recorded that this solution generated delays in cluster activities. However, in most cases, this delay is noticeable but nevertheless acceptable. The proposed method can potentially be a part of real Kubernetes multi-tenant systems where network isolation is one of the essential requirements