Double P-Tree: A Distributed Architecture for Large-Scale Video-on-Demand

Abstract

In order to ensure a more widespread implementation of video-ondemand (VoD) services, it is essential that the design of cost-effective largescale VoD (LVoD) architectures be able to support hundreds of thousands of concurrent users. The main keys for the designing of such architectures are high streaming capacity, low costs, scalability, fault tolerance, load balance, low complexity and resource sharing among user requests. To achieve these objectives, we propose a distributed architecture, called double P-Tree, which is based on a tree topology of independent local networks with proxies. The proxy functionality has been modified in such a way that it works at the same time as cache for the most-watched videos, and as a distributed mirror for the remaining videos. In this way, we manage to distribute main server functionality (as a repository of all system videos, server of proxy-misses and system manager) among all local proxies. The evaluation of this new architecture, through an analytical model, shows that double P-Tree architecture is a good approach for the building of scalable and fault-tolerant LVoD systems. Experimental results show that this architecture achieves a good tradeoff between effective bandwidth and storage requirements.

Designing a Video-on-Demand System for a Brazilian High Speed Network

“…2) but without the need for any centralized repository. In this propose, the Distributed-server is managed using a combined cache-mirror scheme [3] to manage contents.…”

“…Due to infrastructure restrictions, the possible solutions for a VoD system in the Brazilian network are limited to employ a centralized-server [2], independent servers [10], one-level-proxies [4] and distributed servers [3].…”

“…Once VODSim has been utilized to test several VoD proposals [3][11] [12], this paper focuses on the use of the simulator to design a VoD system in a real network infrastructure, located in Brazil.…”

Exploiting Traffic Balancing and Multicast Efficiency in Distributed Video-on-Demand Architectures

“…To improve topology connectivity, several local networks (named brothers networks) from the same level are interconnected, increasing the number of adjacent local networks without changing the topology size or last level width. This new architecture is named Double P-Tree because the brother networks are joined in a second tree within the original tree topology [6].…”

“…In [6] we proposed an architecture for a fully distributed VoD system (called Double P-Tree) which, in addition to supporting a large number of concurrent streams, allows for the distribution of network traffic in order to minimize the network's bandwidth requirements. This is achieved by distributing both the servers as well as the clients throughout the topology, avoiding the concentration of communication traffic on the last level of the hierarchy (head-end).…”