Date Added: Jul 2011
When it comes to reliability, there are two main categories of distributed publish/subscribe systems: reliable systems and best-effort systems. The former gives the highest priority to guaranteed and ordered delivery while the latter aims for high throughput and low delays. The authors propose a method to improve the delivery guarantees of the basic unreliable service offered by a best-effort publish/subscribe system. This method does not require any modification to the system's protocols or broker software, and instead simply uses the system's publish/subscribe API. The method is based on a technique, similar to reliable multicast, that enables subscribers to cooperatively recover lost messages.