Traceability and Timeliness in Messaging Middleware

Abstract

Distributed messaging middleware can provide few delivery guarantees. Nevertheless, applications need to monitor timely delivery of important messages, both at the time and retrospectively, such as for reasons of safety and audit in a healthcare application. Timely, decentralised notification enables out-of-band resolution of problems beyond the messaging system’s control. Instead of relying on applications to generate (and monitor) a proof of delivery message, which may itself be lost in transit, we instead propose a general-purpose service that provides local delivery logs, remote delivery confirmation, and automatic warning events about potentially undelivered messages, in a clean extension of the pub/sub paradigm. The service can also provide an audit trail across a chain of messages, by using message tokens to correlate the receipt and subsequent publication of otherwise apparently unrelated messages. This allows meaningful analysis of failures in a workflow, enabling reliable applications which recover gracefully from communication failures.

An erratum to this chapter can be found at http://dx.doi.org/10.1007/11915072_109.