Every Cloud Has a Push Data Lining: Incorporating Cloud Services in a Context-Aware Application

We investigated context-awareness by utilising multiple sources of context in a mobile device setting. In our experiment we developed a system consisting of a mobile client, running on the Android platform, integrated with a cloud-based service. These components were integrated using pushmessaging technology.One of the key featureswas the automatic adaptation of smartphones in accordance with implicit user needs. The novelty of our approach consists in the use of multiple sources of context input to the system, which included the use of calendar data and web based user configuration tool, as well as that of an external, cloud-based, configuration file storing user interface preferences which, pushed at log-on time irrespective of access device, frees the user from having to manually configure its interface.The systemwas evaluated via two rounds of user evaluations (n = 50 users), the feedback of which was generally positive and demonstrated the viability of using cloud-based services to provide an enhanced context-aware user experience

Reliable Messaging to Millions of Users with MigratoryData

Web-based notification services are used by a large range of businesses to selectively distribute live updates to customers, following the publish/subscribe (pub/sub) model. Typical deployments can involve millions of subscribers expecting ordering and delivery guarantees together with low latencies. Notification services must be vertically and horizontally scalable, and adopt replication to provide a reliable service. We report our experience building and operating MigratoryData, a highly-scalable notification service. We discuss the typical requirements of MigratoryData customers, and describe the architecture and design of the service, focusing on scalability and fault tolerance. Our evaluation demonstrates the ability of MigratoryData to handle millions of concurrent connections and support a reliable notification service despite server failures and network disconnections

SIMPLEstone: Benchmarking Presence Server Performance

Presence is an important enabler for communication in Internet telephony systems. Presence-based services depend on accurate and timely delivery of presence information. Hence, presence systems need to be appropriately dimensioned to meet the growing number of users, varying number of devices as presence sources, the rate at which they update presence information to the network and the rate at which network distributes the user's presence information to the watchers. SIMPLEstone is a set of metrics for benchmarking the performance of presence systems based on SIMPLE. SIMPLEstone benchmarks a presence server by generating requests based on a work load specification. It measures server capacity in terms of request handling capacity as an aggregate of all types of requests as well as individual request types. The benchmark treats different configuration modes in which presence server interoperates with the Session Initiation protocol (SIP) server as one block

SIMPLEstone: Benchmarking Presence Server Performance

Presence is an important enabler for communication in Internet telephony systems. Presence-based services depend on accurate and timely delivery of presence information. Hence, presence systems need to be appropriately dimensioned to meet the growing number of users, varying number of devices as presence sources, the rate at which they update presence information to the network and the rate at which network distributes the user's presence information to the watchers. SIMPLEstone is a set of metrics for benchmarking the performance of presence systems based on SIMPLE. SIMPLEstone benchmarks a presence server by generating requests based on a work load specification. It measures server capacity in terms of request handling capacity as an aggregate of all types of requests as well as individual request types. The benchmark treats different configuration modes in which presence server interoperates with the Session Initiation protocol (SIP) server as one block

Performance Evaluation and Comparison of Distributed Messaging Using Message Oriented Middleware

Message Oriented Middleware (MOM) is an enabling technology for modern event- driven applications that are typically based on publish/subscribe communication [Eugster03]. Enterprises typically contain hundreds of applications operating in environments with diverse databases and operating systems. Integration of these applications is required to coordinate the business process. Unfortunately, this is no easy task. Enterprise Integration, according to Brosey et al. (2001), aims to connect and combines people, processes, systems, and technologies to ensure that the right people and the right processes have the right information and the right resources at the right time [Brosey01]. Communication between different applications can be achieved by using synchronous and asynchronous communication tools. In synchronous communication, both parties involved must be online (for example, a telephone call), whereas in asynchronous communication, only one member needs to be online (email). Middleware is software that helps two applications communicate with one another. Remote Procedure Calls (RPC) and Object Request Brokers (ORB) are two types of synchronous middleware—when they send a request they must wait for an immediate reply. This can decrease an application’s performance when there is no need for synchronous communication. Even though asynchronous distributed messaging using message oriented middleware is widely used in industry, there is not enough work done in evaluating the performance of various open source Message oriented middleware. The objective of this work was to benchmark and evaluate three different open source MOM’s performance in publish/subscribe and point-to-point domains, functional comparison and qualitative study from developers perspective

A survey of communication protocols for internet of things and related challenges of fog and cloud computing integration

The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This article surveys e application layer communication protocols to fulfill the IoT communication requirements, and their potential for implementation in fog- and cloud-based IoT systems. To this end, the article first briefly presents potential protocol candidates, including request-reply and publish-subscribe protocols. After that, the article surveys these protocols based on their main characteristics, as well as the main performance issues, including latency, energy consumption, and network throughput. These findings are thereafter used to place the protocols in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their choice, interoperability, and wider system integration. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture.Peer ReviewedPostprint (author's final draft