Parametric Content-Based Publish/Subscribe

Abstract

Content-based publish/subscribe (CPS) is an appealing abstraction for building scalable distributed systems, e.g., message boards, intrusion detectors, or algorithmic stock trading platforms. More recently, extensions of the abstraction have been proposed for location-based services like vehicular networks, mobile social networking, etc.Although current CPS middleware systems are dynamic in the way they support the joining and leaving of publishers and subscribers, they fall short in supporting subscription adaptations. These are becoming increasingly important across many CPS applications. In algorithmic high frequency trading, for instance, stock price thresholds that are of interest to a trader change rapidly, and gains directly hinge on the reaction time to relevant fluctuations rather than fixed values. In location-aware applications, a subscription is a function of the subscriber location (e.g. GPS coordinates) which inherently changes during motion.The common solution to adapt a subscription consists in a re-subscription, where a new subscription is issued and the superseded one canceled. This incurs substantial overhead in CPS middleware systems, and leads to missed or duplicate events during the transition. In this paper, we explore the concept of parametric subscriptions for capturing subscription adaptations. We discuss desirable and feasible guarantees for corresponding support, and propose novel algorithms for updating routing mechanisms effectively and efficiently in classic decentralized CPS broker overlay networks. Compared to re-subscriptions, our algorithms significantly improve the reaction time to subscription updates without hampering throughput or latency under high update rates. We investigate pathological cases of high frequency subscription oscillations, which could significantly decrease the throughput of CPS systems thereby affecting other subscribers. We propose and evaluate approximations techniques to detect such oscillations and mitigate the event filtering burden they place on the CPS system.We convey analyze the benefits of our support through implementations of our algorithms in two CPS systems, and by evaluating our algorithms on two different application scenarios.

Vehicular content centric network (VCCN)

“…Examples of pub/sub approaches for VANETs can be found in the literature such as [16]. The pub/sub paradigm is well-suited for some VANET applications where drivers/ vehicles indicate their interests about certain types of notifications (e.g., warnings concerning traffic jams only within 1 km from the vehicle's current location) announced by the publishers.…”

“…The basic operation of VCCN requires one Interest to be sent per packet, which may result in high signalling overhead [16,17]. Because of the broadcast shared medium, packets using the same route, or close routes, in opposite directions may severely affect each other: Interests on the forward path may contend with the related content on the reverse path and cause interference between interest and content packets.…”

Bypassing the cloud: Peer-assisted event dissemination for augmented reality games

“…This concept is also known as context-aware publish/subscribe. We refer the interested reader to [5] for more details.…”

Fault-Tolerant Distributed Publish/Subscribe Using Self-Stabilization

“…Twitter, Facebook and IPTV are a few examples of such systems. A publish/subscribe system involves two distinct types of activities: publish (i.e., information production) and subscribe (i.e., information consumption) [1], [2]. The publishers are responsible for announcing the availability of new information to the system, while the subscribers, on the other hand, express their interests, and retrieve the desired information accordingly.…”