Virtualization technologies introduce additional uncertainty and overhead for distributed applications, that may
challenge their timeliness. The additional software abstraction layers of the virtualization software offer powerful
parallel execution environments but, at the same time, reduce the effective performance as additional software
layers are introduced. This requires some fine tuning of, among others, the communication middleware software.
The different resource management mechanisms of the middleware may collide with the specific algorithms
replicated by the underlying virtualization software. The present work characterises the set of steps of a
publish-subscribe communication middleware in a distributed system, enhancing it to suit the communication
scheme of virtualized remote nodes. The potential communication steps are identified, and the overhead introduced
by the execution over the virtualization software is provided by means of a data communication rate
metric; a set of benchmark tests are presented that empirically evaluate the overhead and stability of the most
widely used publish-subscribe (P/S) middleware named DDS (Data Distribution System for real-time systems).
A general purpose cloud computing virtual machine monitor is utilized to identify the side effects and the
drawbacks of the general virtualization technology. Results are obtained on a setting with two different DDS
implementations over a general purpose virtualization software, together with a discussion about the potential
drawbacks of the main communication operations.