Omentum – a peer-to-peer approach for internet-scale virtual microscopy

Abstract

Virtual microscopy is increasingly used for e-learning and medical online exams at universities. Traditional client-server systems support up to a few hundred of users accessing more than 10.000 large microscopic images (each several Gigabyte) and each being able to make interactive annotations. We have developed the first peer-to-peer based solution bringing virtual microscopy to an Internet-scale community. We address data distribution and replication by a novel overlay called Omentum, which is based on a random-graph architecture. Omentum uses a lightweight messaging service for peer communication and supports traffic-free routing-path calculation. Based on the directed random graph the system achieves path compression by walking along inbound links during the actual routing phase. The evaluation shows the efficiency and scalability of the Omentum overlay network, its replication strategy and an administrative communication overhead for creating new replicas around 0.06%.