Engineering a Highly Scalable Object-aware Process Management Engine Using Distributed Microservices

Scalability of information systems has been a research topic for many years and is as relevant as ever with the dramatic increases in digitization of business processes and data. This also applies to process-aware information systems, most of which are currently incapable of scaling horizontally, i.e., over multiple servers. This paper presents the design science artifact that resulted from engineering a highly scalable process management system relying on the object-aware process man-agement paradigm. The latter allows for distributed process execution by conceptually encapsulating process logic and data into multiple in-teracting objects that may be processed concurrently. These objects, in turn, are represented by individual microservices at run-time, which can be hosted transparently across entire server clusters. We present mea-surement data that evaluates the scalability of the artifact on a compute cluster, demonstrating that the current prototypical implementation of the run-time engine can handle very large numbers of users and process instances concurrently in single-case mechanism experiments with large amounts of simulated user input. Finally, the development of scalable process execution engines will further the continued maturation of the data-centric business process management field

Real-Time Context-Aware Microservice Architecture for Predictive Analytics and Smart Decision-Making

The impressive evolution of the Internet of Things and the great amount of data flowing through the systems provide us with an inspiring scenario for Big Data analytics and advantageous real-time context-aware predictions and smart decision-making. However, this requires a scalable system for constant streaming processing, also provided with the ability of decision-making and action taking based on the performed predictions. This paper aims at proposing a scalable architecture to provide real-time context-aware actions based on predictive streaming processing of data as an evolution of a previously provided event-driven service-oriented architecture which already permitted the context-aware detection and notification of relevant data. For this purpose, we have defined and implemented a microservice-based architecture which provides real-time context-aware actions based on predictive streaming processing of data. As a result, our architecture has been enhanced twofold: on the one hand, the architecture has been supplied with reliable predictions through the use of predictive analytics and complex event processing techniques, which permit the notification of relevant context-aware information ahead of time. On the other, it has been refactored towards a microservice architecture pattern, highly improving its maintenance and evolution. The architecture performance has been evaluated with an air quality case study

ClouNS - A Cloud-native Application Reference Model for Enterprise Architects

The capability to operate cloud-native applications can generate enormous business growth and value. But enterprise architects should be aware that cloud-native applications are vulnerable to vendor lock-in. We investigated cloud-native application design principles, public cloud service providers, and industrial cloud standards. All results indicate that most cloud service categories seem to foster vendor lock-in situations which might be especially problematic for enterprise architectures. This might sound disillusioning at first. However, we present a reference model for cloud-native applications that relies only on a small subset of well standardized IaaS services. The reference model can be used for codifying cloud technologies. It can guide technology identification, classification, adoption, research and development processes for cloud-native application and for vendor lock-in aware enterprise architecture engineering methodologies

Enabling Fine-grained Access Control in Flexible Distributed Object-aware Process Management Systems

To increase flexibility, object-aware process management systems enable data-driven process execution and dynamic generation of form-based tasks at run-time. Therefore, a powerful access control concept becomes necessary to define which data elements users may read or write at a given point in time during process execution. The access control concept we present in this paper has been realized in the context of the PHILharmonicFlows framework, which provides a distributed data-driven process execution engine. We present solutions that allow for complex as well as fine-grained permissions and roles, which are granted depending on the states of processes and data elements. We show how one can resolve authorization queries in real-time over multiple business objects and process instances. This constitutes a significant advantage over centralized access control systems

MicroFog: A Framework for Scalable Placement of Microservices-based IoT Applications in Federated Fog Environments

MicroService Architecture (MSA) is gaining rapid popularity for developing large-scale IoT applications for deployment within distributed and resource-constrained Fog computing environments. As a cloud-native application architecture, the true power of microservices comes from their loosely coupled, independently deployable and scalable nature, enabling distributed placement and dynamic composition across federated Fog and Cloud clusters. Thus, it is necessary to develop novel microservice placement algorithms that utilise these microservice characteristics to improve the performance of the applications. However, existing Fog computing frameworks lack support for integrating such placement policies due to their shortcomings in multiple areas, including MSA application placement and deployment across multi-fog multi-cloud environments, dynamic microservice composition across multiple distributed clusters, scalability of the framework, support for deploying heterogeneous microservice applications, etc. To this end, we design and implement MicroFog, a Fog computing framework providing a scalable, easy-to-configure control engine that executes placement algorithms and deploys applications across federated Fog environments. Furthermore, MicroFog provides a sufficient abstraction over container orchestration and dynamic microservice composition. The framework is evaluated using multiple use cases. The results demonstrate that MicroFog is a scalable, extensible and easy-to-configure framework that can integrate and evaluate novel placement policies for deploying microservice-based applications within multi-fog multi-cloud environments. We integrate multiple microservice placement policies to demonstrate MicroFog's ability to support horizontally scaled placement, thus reducing the application service response time up to 54%

Redefining a Process Engine as a Microservice Platform

In recent years, microservice architectures have emerged as an agile approach for scalable web applications on cloud environments. As each microservice is developed and deployed independently, they can be developed in the platform and programming language that best suite their purposes, using a simple communication protocol, as REST APIs or asynchronous event-based collaborations, to compose them. In this paper, we argue that process engines provide an excellent platform to develop microservices whose business logic involves complex work flows or processes so that a Business Process language can be used as high level language to develop these services and a process engine to execute it. We identify the requirements for integrating a process engine in a microservice architecture and we propose how the communication and deployment in a microservice architecture can be handled by the process engine.Ministerio de Economía y Competitividad TIN2015-70560-R (BELI)Junta de Andalucía P12-TIC-1867 (COPAS)Junta de Andalucía P10-TIC-590

Building and monitoring an event-driven microservices ecosystem

Throughout the years, software architectures have evolved deeply to attempt to address the main issues that have been emerging, mainly due to the ever-changing market needs. The need to provide a way for organizations and teams to build applications independently and with greater agility and speed led to the adoption of microservices, particularly endorsing an asynchronous methodology of communication between them via events. Moreover, the evergrowing demands for high-quality resilient and highly available systems helped pave the path towards a greater focus on strict quality measures, particularly monitoring and other means of assuring the well-functioning of components in production in real-time. Although techniques like logging, monitoring, and alerting are essential to be employed for each microservice, it may not be enough considering an event-driven architecture. Studies have shown that although organizations have been adopting this type of software architecture, they still struggle with the lack of visibility into end-to-end business processes that span multiple microservices. This thesis explores how to guarantee observability over such architecture, thus keeping track of the business processes. It shall do so by providing a tool that facilitates the analysis of the current situation of the ecosystem, as well as allow to view and possibly act upon the data. Two solutions have been explored and are therefore presented thoroughly, alongside a detailed comparison with the purpose of drawing conclusions and providing some guidance to the readers. These outcomes that were produced by the thesis resulted in a paper published and registered to be presented at this year’s edition of the SEI hosted at ISEP.Ao longo dos últimos anos, as arquiteturas de software têm evoluído significativamente de forma a tentar resolver os principais problemas que têm surgindo, principalmente derivados nas necessidades do mercado que estão em constante mudança. A necessidade de providenciar uma forma das organizações e suas equipas construírem aplicações independentemente e com uma maior agilidade e rapidez levou à adoção de microserviços, geralmente aplicando uma metodologia de comunicação assíncrona através de eventos. Para além disso, a constante evolução da necessidade de ter sistemas de qualidade e altamente resilientes e disponíveis, ajudou a direcionar um maior foco para padrões de qualidade mais rigorosos, particularmente no que toca a monitorização e outros meios para assegurar o correto funcionamento de componentes em produção em tempo-real. Embora técnicas como a produção de logs, monitorização e alarmística sejam essenciais para ser aplicadas a cada microserviço, poderá não ser suficiente quando consideramos uma arquitetura baseada em eventos. Estudos recentes apontam para que organizações, apesar de estarem a adotar cada vez mais este tipo de arquiteturas de software, ainda encontram bastantes dificuldades devido à falta de visibilidade que possuem dos processos de negócio que envolvem e se propagam por diversos microserviços. Esta tese explora como garantir visibilidade sobre uma arquitetura como a descrita, e assim conseguir seguir os processos de negócio. O resultado da mesma deverá atender a isso providenciando uma ferramenta que facilita a análise da situação atual do ecossistema, e que possibilita a visualização e a intervenção sobre os dados que são disponibilizados. Foram desenvolvidas duas soluções que serão apresentadas detalhadamente juntamente com uma comparação entre as duas com o propósito de tirar mais conclusões e providenciar alguma orientação ao leitor. A tese originou a criação de um artigo submetido para ser apresentado na edição deste ano do SEI

Microservice Transition and its Granularity Problem: A Systematic Mapping Study

Microservices have gained wide recognition and acceptance in software industries as an emerging architectural style for autonomic, scalable, and more reliable computing. The transition to microservices has been highly motivated by the need for better alignment of technical design decisions with improving value potentials of architectures. Despite microservices' popularity, research still lacks disciplined understanding of transition and consensus on the principles and activities underlying "micro-ing" architectures. In this paper, we report on a systematic mapping study that consolidates various views, approaches and activities that commonly assist in the transition to microservices. The study aims to provide a better understanding of the transition; it also contributes a working definition of the transition and technical activities underlying it. We term the transition and technical activities leading to microservice architectures as microservitization. We then shed light on a fundamental problem of microservitization: microservice granularity and reasoning about its adaptation as first-class entities. This study reviews state-of-the-art and -practice related to reasoning about microservice granularity; it reviews modelling approaches, aspects considered, guidelines and processes used to reason about microservice granularity. This study identifies opportunities for future research and development related to reasoning about microservice granularity.Comment: 36 pages including references, 6 figures, and 3 table

Enabling runtime flexibility in data-centric and data-driven process execution engines

Contemporary process management systems support users during the execution of predefined business processes. However, when unforeseen situations occur, which are not part of the process model serving as the template for process execution, contemporary technology is often unable to offer adequate user support. One solution to this problem is to allow for ad-hoc changes to process models, i.e., changes that may be applied on the fly to a running process instance. As opposed to the widespread activity-centric process modeling paradigm, for which the support of instance-specific ad-hoc changes is well researched, albeit not properly supported by most commercial process engines, there is no corresponding support for ad-hoc changes in other process support paradigms, such as artifact-centric or object-aware process management. This article presents concepts for supporting ad-hoc changes in data-centric and data-driven processes, and gives insights into the challenges to be tackled when implementing this kind of process flexibility in the PHILharmonicFlows process execution engine. We evaluated the concepts by implementing a proof-of-concept prototype and applying it to various scenarios. The development of advanced flexibility features is highly relevant for data-centric processes, as the research field is generally perceived as having low maturity compared to activity-centric processes