Lionel Cons (CERN) Massimo Paladin (Universita degli Studi di Udine)
Messaging is seen as an attractive mechanism to simplify and extend several portions of the Grid middleware, from low level monitoring to experiments dashboards. The messaging service currently used by WLCG is operated by EGI and consists of four tightly coupled brokers running ActiveMQ and designed to host the Grid operational tools such as SAM. This service is successfully being used by several Grid operational tools. To improve these services and widen the use of the technology we identified three core aspects that have to evolve: security, scalability and availability/reliability. In this paper we describe the WLCG messaging service, it's future and the technical solutions being put in place to address the anticipated needs while preserving backward compatibility for its current applications.