Design and evaluation of a Pub/Sub service in the cloud

Pub/Sub services in the cloud are intended to achieve high performance and high scalability. The challenge comes from how to deal with the potential wide variation in workloads. The paper constructs a content-based Pub/Sub service named OPS4Cloud on the top of cloud infrastructure from scratch. OPS4Cloud manages its brokers by regions and presents a VM-based region adjustment strategy. It builds two-level indexes at brokers to speed up the routing of subscriptions, events and advertisements on the basis of channelization routing. It also designs a mechanism for subscription persistence, accelerating the load transfer. The paper conducts extensive experiments on OPS4Cloud, especially in comparison with the migrated Pub/Sub systems. The experimental data shows that OPS4Cloud is vastly superior to the migrated systems in terms of system throughput and event response time, and it also tends towards a load-balancing state among brokers while running continuously.