The growing volumes of XML data sources on the Web or produced by
enterprises, organizations etc. raise many performance challenges for data
management applications. In this work, we are concerned with the distributed,
peer-to-peer management of large corpora of XML documents, based on distributed
hash table (or DHT, in short) overlay networks. We present ViP2P (standing for
Views in Peer-to-Peer), a distributed platform for sharing XML documents based
on a structured P2P network infrastructure (DHT). At the core of ViP2P stand
distributed materialized XML views, defined by arbitrary XML queries, filled in
with data published anywhere in the network, and exploited to efficiently
answer queries issued by any network peer. ViP2P allows user queries to be
evaluated over XML documents published by peers in two modes. First, a
long-running subscription mode, when a query can be registered in the system
and receive answers incrementally when and if published data matches the query.
Second, queries can also be asked in an ad-hoc, snapshot mode, where results
are required immediately and must be computed based on the results of other
long-running, subscription queries. ViP2P innovates over other similar
DHT-based XML sharing platforms by using a very expressive structured XML query
language. This expressivity leads to a very flexible distribution of XML
content in the ViP2P network, and to efficient snapshot query execution. ViP2P
has been tested in real deployments of hundreds of computers. We present the
platform architecture, its internal algorithms, and demonstrate its efficiency
and scalability through a set of experiments. Our experimental results outgrow
by orders of magnitude similar competitor systems in terms of data volumes,
network size and data dissemination throughput.Comment: RR-7812 (2011
