Just a couple of cents more. You can expect a lot better experience out of the box in the Foxy release, as things have improved a lot in the meantime.
1.- Discovery over WIFI (@smac): A lot of improvements have been made and both the behavior and the defaults now are specifically tuned for this scenario.
Also, as I promise, here is the first article of a series of intensive experiments with the Raspberry Pi Farm:
Fast-RTPS Server-Client Discovery Analysis
This is available in Dashing, and optimized in foxy. As expected, it works very well for Wifi networks not supporting multicast. We are studying how to simplify even more the configuration required, but it could be as simple as specifying the master in ROS1: if you export an environment variable we could select that discovery mechanism, for example.
2.- Streaming and big data in the intra- process and inter- process case (@Ingo_Lutkebohle): This week we have released Fast RTPS 1.10 (already available), with a complete shared memory transport and optimized intra-process behavior. This feature is the first time is available in an open source implementation of DDS, and as expected decreased the latency and increases the throughput a lot for big messages, such as the used in video streaming.
We are now in the process of characterizing the performance, and we will publish some results soon, but as an example, for a message of 2m the latency decreases around 20 times in the case of inter-process.
This feature is enabled by default, so no configuration required, and it is available in all the ROS 2 supported platforms
3.- Benchmarking as part of our CI: We at eProsima are continuously doing a big effort to improve the performance and scalability having a dedicated team for performance and benchmarking tests as part of our CI. We usually add more scenarios and tests when customers or the community describes any performance issue, and we will stay tuned to keep improving.