Recent advances in industrial wireless sensor networks towards efficient management in IoT

With the accelerated development of Internet-of- Things (IoT), wireless sensor networks (WSN) are gaining importance in the continued advancement of information and communication technologies, and have been connected and integrated with Internet in vast industrial applications. However, given the fact that most wireless sensor devices are resource constrained and operate on batteries, the communication overhead and power consumption are therefore important issues for wireless sensor networks design. In order to efficiently manage these wireless sensor devices in a unified manner, the industrial authorities should be able to provide a network infrastructure supporting various WSN applications and services that facilitate the management of sensor-equipped real-world entities. This paper presents an overview of industrial ecosystem, technical architecture, industrial device management standards and our latest research activity in developing a WSN management system. The key approach to enable efficient and reliable management of WSN within such an infrastructure is a cross layer design of lightweight and cloud-based RESTful web service

Benchmarking Resource Management For Serverless Computing

Serverless computing is a way in which users or companies can build and run applications and services without having to worry about acquiring or maintaining servers and their software stacks. This new technology is a significant innovation because server management incurs a large amount of overhead and can be very complex and difficult to work with. The serverless model also allows for fine-grain billing and demand resource allocation, allowing for better scalability and cost reduction. Academic researchers and industry practitioners agree that serverless computing is an amazing innovation, but it introduces new challenges. The algorithms and protocols currently deployed for virtual server optimization in traditional cloud computing environments are not able to simultaneously achieve low latency, high throughput, and fine-grained scalability while maintaining low cost for the cloud service providers. Furthermore, in the serverless computing paradigm, computation units (i.e., functions) are stateless. Applications, specified through function workflows, do not have control over specific states or their scheduling and placement, which can sometimes lead to significant latency increases and some opportunities to optimize the usage of physical servers. Overcoming these challenges highlights some of the tension between giving programmers control and allowing providers to optimize automatically. This research identifies some of the challenges in exploring new resource management approaches for serverless computing (more specifically, FaaS) as well as attempts to deal with one of these challenges. Our experimental approach includes the deployment of an open-source serverless function framework, OpenFaaS. We focus on faasd, a more lightweight variant of OpenFaaS. Faasd was chosen over the normal OpenFaaS due to not having the higher complexity and cost of Kubernetes. As researchers in academia and industry develop new approaches for optimizing the usage of CPU, memory, and I/O for serverless platforms, the community needs to establish benchmark workloads for evaluating proposed methods. Several research groups have proposed benchmark suites in the last two years, and many others are still in development. A commonality among these benchmark tools is their complexity; for junior researchers without experience in the deployment of distributed systems, a lot of time and effort goes into deploying the benchmarking, hindering their progress in evaluating newly proposed ideas. In our work, we demonstrate that even well-regarded proposals still introduce deficiencies and deployment challenges, proposing that a simplified, constrained benchmark can be useful in preparing execution environments for the experimental evaluation with serverless services

Using Cloud Technologies to Optimize Data-Intensive Service Applications

The role of data analytics increases in several application domains to cope with the large amount of captured data. Generally, data analytics are data-intensive processes, whose efficient execution is a challenging task. Each process consists of a collection of related structured activities, where huge data sets have to be exchanged between several loosely coupled services. The implementation of such processes in a service-oriented environment offers some advantages, but the efficient realization of data flows is difficult. Therefore, we use this paper to propose a novel SOA-aware approach with a special focus on the data flow. The tight interaction of new cloud technologies with SOA technologies enables us to optimize the execution of data-intensive service applications by reducing the data exchange tasks to a minimum. Fundamentally, our core concept to optimize the data flows is found in data clouds. Moreover, we can exploit our approach to derive efficient process execution strategies regarding different optimization objectives for the data flows

Runtime Adaptation of Scientific Service Workflows

Software landscapes are rather subject to change than being complete after having been built. Changes may be caused by a modified customer behavior, the shift to new hardware resources, or otherwise changed requirements. In such situations, several challenges arise. New architectural models have to be designed and implemented, existing software has to be integrated, and, finally, the new software has to be deployed, monitored, and, where appropriate, optimized during runtime under realistic usage scenarios. All of these situations often demand manual intervention, which causes them to be error-prone. This thesis addresses these types of runtime adaptation. Based on service-oriented architectures, an environment is developed that enables the integration of existing software (i.e., the wrapping of legacy software as web services). A workflow modeling tool that aims at an easy-to-use approach by separating the role of the workflow expert and the role of the domain expert. After the development of workflows, tools that observe the executing infrastructure and perform automatic scale-in and scale-out operations are presented. Infrastructure-as-a-Service providers are used to scale the infrastructure in a transparent and cost-efficient way. The deployment of necessary middleware tools is automatically done. The use of a distributed infrastructure can lead to communication problems. In order to keep workflows robust, these exceptional cases need to treated. But, in this way, the process logic of a workflow gets mixed up and bloated with infrastructural details, which yields an increase in its complexity. In this work, a module is presented that can deal automatically with infrastructural faults and that thereby allows to keep the separation of these two layers. When services or their components are hosted in a distributed environment, some requirements need to be addressed at each service separately. Although techniques as object-oriented programming or the usage of design patterns like the interceptor pattern ease the adaptation of service behavior or structures. Still, these methods require to modify the configuration or the implementation of each individual service. On the other side, aspect-oriented programming allows to weave functionality into existing code even without having its source. Since the functionality needs to be woven into the code, it depends on the specific implementation. In a service-oriented architecture, where the implementation of a service is unknown, this approach clearly has its limitations. The request/response aspects presented in this thesis overcome this obstacle and provide a SOA-compliant and new methods to weave functionality into the communication layer of web services. The main contributions of this thesis are the following: Shifting towards a service-oriented architecture: The generic and extensible Legacy Code Description Language and the corresponding framework allow to wrap existing software, e.g., as web services, which afterwards can be composed into a workflow by SimpleBPEL without overburdening the domain expert with technical details that are indeed handled by a workflow expert. Runtime adaption: Based on the standardized Business Process Execution Language an automatic scheduling approach is presented that monitors all used resources and is able to automatically provision new machines in case a scale-out becomes necessary. If the resource's load drops, e.g., because of less workflow executions, a scale-in is also automatically performed. The scheduling algorithm takes the data transfer between the services into account in order to prevent scheduling allocations that eventually increase the workflow's makespan due to unnecessary or disadvantageous data transfers. Furthermore, a multi-objective scheduling algorithm that is based on a genetic algorithm is able to additionally consider cost, in a way that a user can define her own preferences rising from optimized execution times of a workflow and minimized costs. Possible communication errors are automatically detected and, according to certain constraints, corrected. Adaptation of communication: The presented request/response aspects allow to weave functionality into the communication of web services. By defining a pointcut language that only relies on the exchanged documents, the implementation of services must neither be known nor be available. The weaving process itself is modeled using web services. In this way, the concept of request/response aspects is naturally embedded into a service-oriented architecture