We talked through the definition of journaling and how it differs from logging.  Looked at the benefits of journaling to a system.1) Black box testing2) Remoting3) Dealing with back pressure.Looked at the open source project https://github.com/danielshaya/reactivejournal for concrete examples of how to integrate journaling into a Reactive system in the simplest way.  Discussed how to to write a Reactive Publisher and the threading implications.  Discussed the problems of dealing with back pressure by using an in memory buffer.