Combining caching with a cloud hosted proxy to support mobile consumers of RESTful services

There are numerous problems to be addressed when connecting mobile clients (e.g. smartphones and tablet devices) with Web services. These devices consume Web services via wireless channels; and as a result, developers and researchers are investigating different approaches to address challenges related to network fluctuation, latency, and low bandwidth. In addition, most of these devices have limited capabilities in terms of information processing and resource storage. This research focuses on enabling mobile devices for consuming RESTful Web services efficiently. The aforementioned problems of network instability are addressed in this research by proposing and implementing a cloud centric proxy server architecture; which is based on mirroring resources. The mirroring of the Web server’s resources on the mobile device and the proposed proxy server is achieved by exploring caching techniques. Furthermore, an evaluation is done to determine what kind of components and architecture is required for supporting resource constraint mobile devices like smartphones and tablets while connecting them with RESTful systems. By linking the caching components of the mobile devices with a cloud-hosted proxy server, it becomes possible to share caches and achieve significant performance boost for mobile consumers of the RESTful Web services

Optimasi Pengunduhan Anime Jepang Bersubtitle Indonesia dengan Metode Restful API dan Firebase Cloud Messaging

(RESTful API / REST API merupakan penerapan dari API (Application Programming Interface). Sedangkan REST (Representional State Transfer) adalah sebuah arsitektur metode komunikasi yang menggunakan protokol HTTP untuk pertukaran data dimana metode ini sering diterapkan dalam pengembangan aplikasi. Dengan tujuannya untuk menjadikan sistem memiliki performa yang baik, cepat dan mudah untuk di kembangkan (scale) terutama dalam pertukaran dan komunikasi data. Firebase Cloud Message (FCM) adalah adalah solusi pertukaran pesan lintas platform yang dapat digunakan untuk mengirim pesan tanpa biaya. Dengan FCM, Anda dapat memberi tahu aplikasi klien bahwa pesan baru atau data lainnya tersedia untuk disinkronkan. Penelitian pengembangan system menggunakan metode Prototype, metode ini cocok digunakan untuk mengembangkan sebuah perangkat lunak yang dikembangkan kembali. Metode ini membuat sebuah rancangan kilat yang selanjutnya akan dievaluasi kembali sebelum di produksi secara benar. Hasil penelitian menunjukan bahwa Aplikasi dengan menggunakan firebase cloud message dapat membantu pengguna dalam mendapatkan kabar atau pembaruan yang sedang terjadi

Rendering real-time dashboards using a GraphQL-based UI Architecture

With the increase in the complexity of the systems being built and demand in the quality of service by the customers, developing and providing highly efficient real-time systems is one of the biggest challenges today for software enterprises. BluemixTM ─ IBM’s cloud offering implemented on Cloud Foundry, an open source “Platform as a Service” (PaaS), is an example of such a system. Currently, there are approx. 26 infrastructural services running in the background from where the data is fetched and is rendered on different dashboards of the system. However, the system suffers from performance issues. This thesis explores the performance improvements of the real-time dashboards by introducing our proposed GraphQL-based UI architecture which allows caching and asynchronous loading. The test results of this architecture’s implementation on the Bluemix Usage Dashboard show that the Real data renders 245% faster and the Switching Account 153% faster than the existing system

Pre-study on Multi-access Edge Computing at Communication Technology lab: simulator/emulator

Multi-access edge computing has been on the rise since the evolution of 5G. There are challenges that 5G has been fighting with, such as latency and data being transferred. In this paper, it will talk about the background of Multi-access edge computing, the state of the art of Multi-access edge computing research and then implementing a simulator to demonstrate Multi-access edge computing functionalities

IMPLEMENTATION AND EVALUATION OF A GRAPHQL-BASED WEB APPLICATION FOR PROJECT FOLLOW UP

This thesis is about APIs and web development. Technologies specifically presented include GraphQL and REST as a basis for the implementation of the web application. The purpose of the thesis was to create a web-based tool for project follow up. The main goal of the tool is to provide reporting functionalities and views for project follow up based on data from the public APIs provided by Toggl. In the first part of the thesis, relevant theory about GraphQL, REST and APIs is provided. Web APIs are presented, along with common protocols, such as HTTP, as well as different data formats for the serialization of the data to be transmitted over the net-work. A literature review is also performed on the current state of the research on GraphQL-based APIs as well as on comparisons on GraphQL-, and RESTful-APIs. The second part consists of the design and implementation of the application. Toggl, a time tracking service, is described with its two different APIs, the Toggl API, and the Report API. Further, the decision process of selecting the technologies for the developed tool is presented. One of the main parts of the tool consists of the synchronization mechanism for keeping the data in the database up to date with the data stored in Toggl. The other major part is about exposing the data via a GraphQL-API and consuming it in a single-page-application created in React. The developed application is a minimum viable product, fulfilling its purpose of providing reporting functionalities for projects based on the data provided by Toggl. It was developed with usability, flexibility and testability in mind enabling further development in the future. GraphQL was the choice of API technology and was considered a suitable approach in this applicatio

RESTful Service Composition

The Service-Oriented Architecture (SOA) has become one of the most popular approaches to building large-scale network applications. The web service technologies are de facto the default implementation for SOA. Simple Object Access Protocol (SOAP) is the key and fundamental technology of web services. Service composition is a way to deliver complex services based on existing partner services. Service orchestration with the support of Web Services Business Process Execution Language (WSBPEL) is the dominant approach of web service composition. WSBPEL-based service orchestration inherited the issue of interoperability from SOAP, and it was furthermore challenged for performance, scalability, reliability and modifiability. I present an architectural approach for service composition in this thesis to address these challenges. An architectural solution is so generic that it can be applied to a large spectrum of problems. I name the architectural style RESTful Service Composition (RSC), because many of its elements and constraints are derived from Representational State Transfer (REST). REST is an architectural style developed to describe the architectural style of the Web. The Web has demonstrated outstanding interoperability, performance, scalability, reliability and modifiability. RSC is designed for service composition on the Internet. The RSC style is composed on specific element types, including RESTful service composition client, RESTful partner proxy, composite resource, resource client, functional computation and relaying service. A service composition is partitioned into stages; each stage is represented as a computation that has a uniform identifier and a set of uniform access methods; and the transitions between stages are driven by computational batons. RSC is supplemented by a programming model that emphasizes on-demand function, map-reduce and continuation passing. An RSC-style composition does not depend on either a central conductor service or a common choreography specification, which makes it different from service orchestration or service choreography. Four scenarios are used to evaluate the performance, scalability, reliability and modifiability improvement of the RSC approach compared to orchestration. An RSC-style solution and an orchestration solution are compared side by side in every scenario. The first scenario evaluates the performance improvement of the X-Ray Diffraction (XRD) application in ScienceStudio; the second scenario evaluates the scalability improvement of the Process Variable (PV) snapshot application; the third scenario evaluates the reliability improvement of a notification application by simulation; and the fourth scenario evaluates the modifiability improvement of the XRD application in order to fulfil emerging requirements. The results show that the RSC approach outperforms the orchestration approach in every aspect

Web services approach for ambient assisted living in mobile environments

Web services appeared as a promising technology for Web environments independent of technologies, services, and applications. First, a performance comparison study between the two most used Web service architectures, SOAP and REST, is presented, considering messages exchange between clients and a server. Based on this study, the REST architecture was chosen to deploy the system because it gets better results compared to SOAP architecture. Currently, there are some issues related with this approach that should be studied. For instance, if massive quantities of data are sent to databases it can influence significantly the performance of the whole system. The Advanced Message Queuing Protocol (AMPQ) appears as a promising solution to address this problem. Then, in order to evaluate the performance of this approach, this work presents a performance evaluation and a comparison study of RESTful Web services and the AMQP Protocol considering exchanging messages between clients and a server. The study is based on the averaged exchanged messages for a certain period of time. It was observed and concluded that, for large quantities of messages exchange, the best results comes from the Advanced Message Queuing Protocol. Message Queuing Telemetry Transport (MQTT) was addressed in this work because it is a similar protocol to AMQP but it can be used by mobile devices with a processing capacity smallest unlike the AMQP that needs greater processing capacity. These studies are performed in the context of Ambient Assisted Living environments, since the work was applied to this topic in order to experiment the effectiveness and evaluate the performance of these protocols in this scenario

Provision of adaptive and context-aware service discovery for the Internet of Things

The IoT concept has revolutionised the vision of the future Internet with the advent of standards such as 6LoWPAN making it feasible to extend the Internet into previously isolated environments, e.g., WSNs. The abstraction of resources as services, has opened these environments to a new plethora of potential applications. Moreover, the web service paradigm can be used to provide interoperability by offering a standard interface to interact with these services to enable WoT paradigm. However, these networks pose many challenges, in terms of limited resources, that make the adaptability of existing IP-based solutions infeasible. As traditional service discovery and selection solutions demand heavy communication and use bulky formats, which are unsuitable for these resource-constrained devices incorporating sleep cycles to save energy. Even a registry based approach exhibits burdensome traffic in maintaining the availability status of the devices. The feasible solution for service discovery and selection is instrumental to enable the wide application coverage of these networks in the future. This research project proposes, TRENDY, a new compact and adaptive registry-based SDP with context awareness for the IoT, with more emphasis given to constrained networks, e.g., 6LoWPAN It uses CoAP-based light-weight and RESTful web services to provide standard interoperable interfaces, which can be easily translated from HTTP. TRENDY's service selection mechanism collects and intelligently uses the context information to select appropriate services for user applications based on the available context information of users and services. In addition, TRENDY introduces an adaptive timer algorithm to minimise control overhead for status maintenance, which also reduces energy consumption. Its context-aware grouping technique divides the network at the application layer, by creating location-based groups. This grouping of nodes localises the control overhead and provides the base for service composition, localised aggregation and processing of data. Different grouping roles enable the resource-awareness by offering profiles with varied responsibilities, where high capability devices can implement powerful profiles to share the load of other low capability devices. Thus, it allows the productive usage of network resources. Furthermore, this research project proposes APPUB, an adaptive caching technique, that has the following benefits: it allows service hosts to share their load with the resource directory and also decreases the service invocation delay. The performance of TRENDY and its mechanisms is evaluated using an extensive number of experiments performed using emulated Tmote sky nodes in the COOJA environment. The analysis of the results validates the benefit of performance gain for all techniques. The service selection and APPUB mechanisms improve the service invocation delay considerably that, consequently, reduces the traffic in the network. The timer technique consistently achieved the lowest control overhead, which eventually decreased the energy consumption of the nodes to prolong the network lifetime. Moreover, the low traffic in dense networks decreases the service invocations delay, and makes the solution more scalable. The grouping mechanism localises the traffic, which increases the energy efficiency while improving the scalability. In summary, the experiments demonstrate the benefit of using TRENDY and its techniques in terms of increased energy efficiency and network lifetime, reduced control overhead, better scalability and optimised service invocation time

Design of a back-end for a camera based person detection system

In this thesis, a back-end web server is developed for the CityTrack project. The project uses modern Deep Learning techniques to provide object and people detection on embedded devices. By using multiple of these devices, detection nodes, statistical data can be collected about a certain venue or event. To expand this project, a web application is needed to visualise the data with the possibility to watch in real time. In addition to the web application, a central database should be established to provide long-time structured storage for the detection data. To make well-considered choices, different technologies are discussed and weighed against each other. For instance, for the communication between the detection nodes and the web application, the HTTP-based REST architectural style and SOAP protocol are compared to the MQTT protocol. Furthermore, the real time capable communication technologies WebSocket, SeverSent Event and HTTP Long Polling is reviewed. The system uses the REST architectural style due to practical implementation reasons and WebSocket due to the limitations of the other alternatives. The layered architecture is then discussed to arrive at a proposal for a more modern version of the web architecture. The theoretical background and implementations of all components are then discussed. The advantages and disadvantages of each implementation are reviewed and a thoughtful choice was made. To make a sustained choice, the performance of different WSGI server implementations are tested. A WSGI server is an interface between a web server and a Python-based framework. The ApacheBench stress testing tool examines different aspects of the performance. The result is that the uWSGI server performs the best on both latency and throughput aspect compared to the other candidates tested. Also, the performance of the various implementations of ASGI server has been tested analogously. An ASGI interface is a superset of WSGI with additional support for asynchronous communication technologies. Implementations of the ASGI interface are tested on the WSGI functionalities. In this way, it is investigated whether the current implementation of ASGI could replace the WSGI server. The results show that the current implementations of various ASGI servers underperform to replace a WSGI server