Peer-to-peer information systems have gained prominence of late with applications such as file sharing systems and grid computing. However, the information retrieval component of these systems is still limited because traditional techniques for searching and ranking are not directly applicable. This work compares search in peer-to-peer information systems to that in metasearch engines, and desc...

Implementing peer-to-peer systems correctly is difficult due to the extreme situations under which these systems are designed to operate. Unlike in other types of distributed systems, in peer-to-peer systems, arbitrary machines can participate in the system, and machines can leave and join the network at any time. This distinction makes it challenging to formally reason about these types of sys...

Peer to peer systems are large scale distributed systems in which each node has the same role as any other node. Due to their size, these systems distribute the global knowledge of the whole list of peers onto the system such that no one node has the list of all the other nodes. A peer sampling service links the nodes together, forming a connected topology. To write distributed algorithms for p...

Pathway Tools is a production-quality software environment for creating a type of modelorganism database (MOD) called a Pathway/Genome Database (PGDB). A PGDB such as EcoCyc integrates the evolving understanding of the genes, proteins, metabolic network, and regulatory network of an organism. This article provides an overview of Pathway Tools capabilities. The software performs multiple computa...