Split and Migrate: Resource-Driven Placement and Discovery of Microservices at the Edge

Microservices architectures combine the use of fine-grained and independently-scalable services with lightweight communication protocols, such as REST calls over HTTP. Microservices bring flexibility to the development and deployment of application back-ends in the cloud. Applications such as collaborative editing tools require frequent interactions between the front-end running on users\u27 machines and a back-end formed of multiple microservices. User-perceived latencies depend on their connection to microservices, but also on the interaction patterns between these services and their databases. Placing services at the edge of the network, closer to the users, is necessary to reduce user-perceived latencies. It is however difficult to decide on the placement of complete stateful microservices at one specific core or edge location without trading between a latency reduction for some users and a latency increase for the others. We present how to dynamically deploy microservices on a combination of core and edge resources to systematically reduce user-perceived latencies. Our approach enables the split of stateful microservices, and the placement of the resulting splits on appropriate core and edge sites. Koala, a decentralized and resource-driven service discovery middleware, enables REST calls to reach and use the appropriate split, with only minimal changes to a legacy microservices application. Locality awareness using network coordinates further enables to automatically migrate services split and follow the location of the users. We confirm the effectiveness of our approach with a full prototype and an application to ShareLatex, a microservices-based collaborative editing application

Design and realization of a middleware for mobile task coordination

The trend towards interconnection of applications has long been recognized as a key challenge for information systems design. Following this trend, organi- zations have developed and introduced many distributed systems with differ- ent functionalities. Furthermore, computing becomes today increasingly mobile; performances of mobile devices (i.e. PDAs and smartphones) as well as the expansion of high-speed mobile networks allows many tasks to be performed beyond stationary workspaces. The dramatic growth of stand-alone and partly incompatible applications will negatively affect the integration, coordination and communication for entire so- lution. Contemporary solutions focus on stationary systems only; the usage of mobile devices is limited to simple scenarios (i.e. information access). In order to support the seamless integration of mobile devices, future distributed solutions should take services and service meta-information into account (e.g. variation of network bandwidth, battery power, availability, connectivity, reachability, sensors data and locations of services and service providers). In this master thesis we want to analyze how a distributed environment with va- riety of separated (mobile) service providers - implemented with different tech- nologies - can be integrated and coordinated. Finding compromises between performance, comfort and intelligent intercommunication is the main goal of this thesis. Therefore, it is concentrated on the conceptualization and design of a central middleware component that provide the coordination and communication functionalities for stationary and mobile entities. In order to prove some possible communication scenarios, the thesis provides a middleware-based scenario

HTTP Mailbox - Asynchronous RESTful Communication

We describe HTTP Mailbox, a mechanism to enable RESTful HTTP communication in an asynchronous mode with a full range of HTTP methods otherwise unavailable to standard clients and servers. HTTP Mailbox allows for broadcast and multicast semantics via HTTP. We evaluate a reference implementation using ApacheBench (a server stress testing tool) demonstrating high throughput (on 1,000 concurrent requests) and a systemic error rate of 0.01%. Finally, we demonstrate our HTTP Mailbox implementation in a human assisted web preservation application called "Preserve Me".Comment: 13 pages, 6 figures, 8 code blocks, 3 equations, and 3 table

Architecting end-to-end convergence of web and Telco services

International audienceOver the last few years, significant evolutions such as the mobile phones' enhanced Web-browsing capabilities and the technical incursion of Web major players into the Telco world (e.g. Google, Facebook) have reduced the gap between Telecom and Web worlds. In this context, converging IMS or Internet Protocol Multimedia Subsystem and Web service platforms has become a key challenge that needs to be addressed by both Web and telecom players. Several interesting solutions, illustrating different convergence approaches, have been proposed so far. Unfortunately, none of them has been able to provide an efficient way to set up end-to-end converging services. Indeed, Web-based applications are synchronous, as they rely on HTTP. On the other hand, IMS services can be provided in both asynchronous and synchronous modes. We define synchronous applications as services in which each provided resource or piece of information has to be explicitly requested by the consumer and asynchronous applications as services that can notify their consumers anytime they need. But recently, the W3C and the IETF have released new standards (HTML5 and Websocket protocol), introducing important evolutions in the Web paradigm. In particular, the Websocket technology allows a native support for asynchronous Web applications. Our proposal is a converging framework (called WSE, standing for WebSocket Enabler) that takes advantage of this new technology to achieve end-to-end service convergence

N-Screen Application Framework

Smartphones and tablets with advanced computing ability and connectivity have already become indispensable in our daily lives. As operating systems of these computer-like handheld devices are getting more mature and stable, many users want physically separated devices to interact with one another and with shared resources in real time. Those devices may have the same type of operating systems, such as sharing between android smartphone and tablets. However, sometimes the sharing occurs among different operating systems. A user may want to use a smartphone to control the menu while the image presentation is displaying on the Internet Protocol television (IPTV), as well as the audio on a personal computer. This scenario brings about the motivation of this thesis. This thesis proposes an architecture that allows for sharing resources among many devices with separated screens at real-time. Compared with traditional mobile application framework, instead of the user experience on a specific device, the consistent user experience across multiple devices becomes the key concern. This research introduces a novel approach to implement the classical Model-View-Controller (MVC) framework in a distributed manner with a multi-layered distributed controller. To ensure consistent user experiences across multiple devices with di erent platforms, this research also adopts a channel-based Publish/Subscribe with effective server push state synchronization. The experiments evaluate the portability, message travelling latency improvement and bandwidth optimization. The results of those experiments prove the advantages of the n-Screen Application Framework (NSAF) both in portability that allows deployment on multiple devices from different manufacturers and performance improvement (both in latency and bandwidth consumption) while comparing with traditional data dissemination scenarios