A Repair Mechanism for Fault-Tolerance for Tree-Structured Peer-to-Peer Systems

Abstract

Abstract. Facing the limits of traditional tools of resource management within computational grids (related to scale, dynamicity, etc. of the platforms newly considered), new approaches, based on peer-to-peer technologies are emerging. The resource discovery and in particular the service discovery is concerned by this evolution. Among the solutions, a promising one is the indexing of resources using trie structures and more particularly prefix trees. The major advantages of trie-structured approaches is the capability to support search queries on ranges of values with a latency growing logarithmically in the number of nodes in the trie. Those techniques are easy to extend to multicriteria searches. One drawback of using tries is its inherent poor robustness in a dynamic environment, where nodes join and leave the network, leading to the split of the tree into a forest, which results in the impossibility to route requests. Within most recent approaches, the fault-tolerance is a prevention mechanism, often replication-based. The replication can be costly in term of resources required. In this paper, we propose a faulttolerance protocol that reconnects subtrees a posteriori, after crashes, to have again a connected graph and then reorder the nodes to rebuild a consistent tree.

Snap-Stabilizing Prefix Tree for Peer-to-Peer Systems

“…In [10], we provided a first alternative to the replication approach. The idea was to let the trie crash and to a posteriori reconnect and reorder the nodes.…”

Habilitation à diriger des recherches

“…To summarize, the fault tolerance issue is mostly either ignored, delegated or based on replication. In [48], we provided a first alternative to the replication approach. The idea was to let the trie crash and to reconnect and reorder the nodes rounds build is the x However, this protocol assumed the validity of subtries being reordered, thus limiting the field of initial configurations handled and repaired.…”

Physical Expander in Virtual Tree Overlay

“…In particular, tree overlays recently becomes an attractive class of overlay networks because efficient implementations of various communication primitives in P2P systems tied to the hierarchical and acyclic properties of trees such as content-based publish/subscribe or multicast ( [4,6,9,14]). Many P2P and distributed variants of classical tree structures such as B-trees, R-trees or P-trees have been designed so far [1,5,7,8,17,18].…”