Empirical Evaluation of Content-based Pub/Sub Systems over Cloud Infrastructure

Pub/Sub systems permit users to submit subscriptions and notify interested users of the events detected in a distributed way. Moving a Pub/Sub system to a cloud infrastructure is for high performance and scalability. This paper describes how to migrate two Pub/Sub systems i.e. PADRES and Once Pub Sub to Xen Cloud Platform, especially proposes black-box method, grey-box method and white-box method so as to take full advantage of cloud mechanisms. This paper then conducts a series of experiments on the Pub/Sub systems in the cloud to evaluate benefits and costs. The experimental results indicate that the black-box method does not always take effect although it can be implemented easily, the grey-box method is more appropriate to a Pub/Sub system if its workload features and brokers´ roles are known in advance. Further, the experimental results show the white-box method, combined the load balance mechanism both in the cloud and in a Pub/Sub system, can achieve satisfying performance and scalability especially facing the workload with unidentified distribution.