XenoSearch: distributed resource discovery in the XenoServer open platform

We describe the XenoSearch system for performing expressive resource discovery searches in a distributed environment. We represent server meta-data, such as their locations and facilities, as points in a multi-dimensional space and then express queries as predicates over these points. Each XenoSearch node holds a portion of this space and the key goal of XenoSearch is to direct queries to those nodes containing the meta-data of matching XenoServers. Communication between these XenoSearch nodes is based on the self-organizing Pastry peer-to-peer routing substrate. Our initial performance evaluation on a wide-area prototype shows that queries are only a factor of 3 to 5 times longer than basic Pastry routing, while supporting multi-dimensional searches of arbitrary shapes.