Dynamic Management of CORBA Trader Federation

In Wide Area Networks, tools for discovering objects that provide a given service, and for choosing one out of many are essential. The CORBA trading service is one of these tools. A trader federation extends the limit of a discovery, thanks to the cooperation of sev-eral trading servers. However, in a federation, coop-eration links are manually and statically established. In this article, we propose an Extended Trading Serv-ice, which manages a trader federation dynamically. With Extended Trading Service, optimized links be-tween traders are automatically set up thanks to the use of a minimum-weight spanning tree. Cycles in discovery propagation are eliminated. Links evolve dynamically in order to adapt to the modification of the underlying topology and the failure of an interme-diate trader or link. The Extended Trading Service is able to organize discovered objects from the nearest to the furthest according to a distance function chosen for the federation. Such management is provided by spe-cialized trading servers conforming to OMG Trading Service Specification.