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

DIVERSIFY: Ecology-inspired software evolution for diversity emergence

update for BASE on Sep 08 2018 22:43:36International audienceDIVERSIFY is an EU funded project, which aims at favoring spontaneous diversification in software systems in order to increase their adaptive capacities. This objective is founded on three observations: software has to constantly evolve to face unpredictable changes in its requirements, execution environment or to respond to failure (bugs, attacks, etc.); the emergence and maintenance of high levels of diversity are essential to provide adaptive capacities to many forms of complex systems, ranging from ecological and biological systems to social and economical systems; diversity levels tend to be very low in software systems. DIVERSIFY explores how the biological evolutionary mechanisms, which sustain high levels of biodiversity in ecosystems (speciation, phenotypic plasticity and natural selection) can be translated in software evolution principles. In this work, we consider evolution as a driver for diversity as a means to increase resilience in software systems. In particular, we are inspired by bipartite ecological relationships to investigate the automatic diversification of the server side of a client-server architecture. This type of software diversity aims at mitigating the risks of software monoculture. The consortium gathers researchers from the software-intensive, distributed systems and the ecology areas in order to transfer ecological concepts and processes as software design principles

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

Model-based Continuous Deployment of SIS

This chapter is organized as follows. Section 4.2 provides an overview of the current state of the art and of the practice for the automatic deployment of SIS. Section 4.3 introduces our solutions for the automatic deployment of SIS, first describing how they can be integrated in order to form a coherent deployment bundle and then detailing each our two enablers: GENESIS and DivENACT. Section 4.4 focus on the support offered by our solutions to ensure the trustworthiness deployment of SIS. Finally, Section 4.5 draws some conclusions.publishedVersio

Unifying Runtime Adaptation and Design Evolution

International audienceThe increasing need for continuously available software systems has raised two key-issues: self-adaptation and design evolution. The former one requires software systems to monitor their execution platform and automatically adapt their configuration and/or architecture to adjust their quality of service (optimization, fault-handling). The later one requires new design decisions to be reflected on the fly on the running system to ensure the needed high availability (new requirements, corrective and preventive maintenance). However, design evolution and selfadaptation are not independent and reflecting a design evolution on a running self-adaptative system is not always safe. We propose to unify run-time adaptation and run-time evolution by monitoring both the run-time platform and the design models. Thus, it becomes possible to correlate those heterogeneous events and to use pattern matching on events to elaborate a pertinent decision for run-time adaptation. A flood prediction system deployed along the Ribble river (Yorkshire, England) is used to illustrate how to unify design evolution and run-time adaptation and to safely perform runtime evolution on adaptive systems

Modeling the Variability Space of Self-Adaptive Applications

International audienceModeling self-adaptive applications is a difficult task due to the complex relationships they have with their environments. Designers of such applications strive to model accurately a few (re)-configuration possibilities deemed to be the most relevant with respect to environmental changes. This deliberate restriction of the variability space is cumbersome and may unnecessarily reject interesting (re)-configuration possibilities. We employ software product-line techniques to properly cover the whole variability space of a self-adaptive application. This variability space is partitioned across three dimensions. Functional variability is modeled through a feature diagram whose features are realized by a set of components to be deployed on a platform. Topological variability is modeled via an UML collaboration excluding irrelevant configurations. Platform variability is modeled through constraints to be satisfied by configurations. For each dimension, we exhibit properties capturing the environment. Our modeling approach is illustrated on a web-server example

Expression qualitative de politiques d'adaptation pour Fractal

National audienceLes plates-formes d'exécution récentes telles que Fractal ou Open- COM offrent de nombreuses facilités pour assurer la prise en compte de propriétés extra-fonctionnelles (introspection, sondes, chargement dynamique, etc). Cependant, l'intégration de politiques d'adaptation reste délicate car elle nécessite de corréler la configuration du système avec l'évolution de son environnement. Le travail présenté dans cet article propose une description qualitative des évolutions de l'environnement et une interprétation possible basée sur de la logique floue. L'article présente également une extension de la plate-formeFractal implémentant les mécanismes nécessaires à l'exécution de ces politiques d'adaptation de haut niveau. L'approche est illustrée à l'aide d'un serveur HTTP qui modifie sa configuration (architecturale et locale) en fonction de plusieurs paramètres extra-fonctionnels tels que la charge du serveur et la dispersion des requêtes

Reasoning about and Harmonizing the Interaction Behavior of Networked Systems at Application- and Middleware- Layer

The CONNECT Integrated Project aims at enabling continuous composition of networked systems to respond to the evolution of functionalities provided to and required from the networked environment. CONNECT aims at dropping the interoperability barrier by adopting a revolutionary approach to the seamless networking of digital systems, that is, synthesizing on-the-fly the connectors via which networked systems communicate. The resulting emergent connectors are effectively synthesized according to the behavioral semantics of application- down to middleware-layer protocols run by the interacting parties. The role of work package WP3 is to devise automated and compositional approaches to connector synthesis, which can be performed at run-time. Given the respective interaction behavior of networked systems, we want to synthesize the behavior of the connector(s) needed for them to interact. These connectors serve as mediators of the networked systems' interaction at both application and middleware layers. During the project's first year, the work of WP3 led us to achieve the following preliminary results: the formalization of matching and mapping relationships for application-layer interaction protocols; the definition of the corresponding mediator generation algorithm; the analysis of the interoperability problems, and related solutions, that can occur at middleware-layer; and a model-driven approach to the automated elicitation of application-layer protocols from software implementations. All these achievements have been reported in Deliverable D3.1: "Modeling of application- and middleware-layer interaction protocols". In this deliverable, we go a step forward with respect to some of the previous achievements by delivering a unified process, and related artefacts, for the automated synthesis of mediators at both application and middleware layers, code-generation techniques to generate the actual code that implements a synthesized mediator, and a preliminary integration of QoS management in the synthesis process. During year 2, all the work has been validated through its application to several scenarios, in particular as part of WP1 and WP6. By selecting one of them as common scenario, in this deliverable, we also show the different methods/techniques at work on the scenario. All the steps of the devised synthesis process are described in detail and applied to the selected common scenario

Intermediate CONNECT Architecture

Interoperability remains a fundamental challenge when connecting heterogeneous systems which encounter and spontaneously communicate with one another in pervasive computing environments. This challenge is exasperated by the highly heterogeneous technologies employed by each of the interacting parties, i.e., in terms of hardware, operating system, middleware protocols, and application protocols. The key aim of the CONNECT project is to drop this heterogeneity barrier and achieve universal interoperability. Here we report on the activities of WP1 into developing the CONNECT architecture that will underpin this solution. In this respect, we present the following key contributions from the second year. Firstly, the intermediary CONNECT architecture that presents a more concrete view of the technologies and principles employed to enable interoperability between heterogeneous networked systems. Secondly, the design and implementation of the discovery enabler with emphasis on the approaches taken to match compatible networked systems. Thirdly, the realisation of CONNECTors that can be deployed in the environment; we provide domain specific language solutions to generate and translate between middleware protocols. Fourthly, we highlight the role of ontologies within CONNECT and demonstrate how ontologies crosscut all functionality within the CONNECT architecture

Initial CONNECT Architecture

Interoperability remains a fundamental challenge when connecting heterogeneous systems which encounter and spontaneously communicate with one another in pervasive computing environments. This challenge is exasperated by the highly heterogeneous technologies employed by each of the interacting parties, i.e., in terms of hardware, operating system, middleware protocols, and application protocols. The key aim of the CONNECT project is to drop this heterogeneity barrier and achieve universal interoperability. Here we report on the development of the overall CONNECT architecture that will underpin this solution; in this respect, we present the following contributions: i) an elicitation of interoperability requirements from a set of pervasive computing scenarios, ii) a survey of existing solutions to interoperability, iii) an initial view of the CONNECT architecture, and iv) a series of experiments to provide initial validation of the architecture