Is FastDDS v2.14.1 backwards compatible with FastDDS v2.1.4?

[gstangel]

Hi there, this is a general question about backwards compatibility. I am developing a distributed system based around ROS2 Foxy, which uses FastDDS v2.1.4 under the hood. I would like to leverage some newer features in v2.14.1, like the ability to launch a discovery server from a XML file, so I built FastDDS from source. I an unable to get the Discovery Server, running on v2.14.1, working with the ROS2 Foxy Nodes, running v2.1.4. I was wondering if anyone would be able to point me in a direction that would define what versions of FastDDS are compatible with each other. I am able to get the Discovery Server working when it is running at the same version as the ROS2 Foxy Nodes (v2.1.4).

Thanks!

[Mario-DL]

Hi @gstangel,
Thanks for using Fast DDS. In general terms we cannot guarantee that the behavior and ABI of v2.14.1 is compatible with v2.1.4 (that was deprecated a year ago) in all its features, what we can assure is that there is no API breaks within these two (VERSIONING).

Anyways, please ensure that the client and server settings are correct (address, port and index). For further documentation you can refer to (Discovery Server)

[devrite]

I face a similar issue I use humble (2.6.8). If I build the DDSRouter WS it also builds it's own dds libs. If I launch the discovery server via ddsrouter or via fastdds discoery from the ws directly I can not get humble to connect to that router. If I use the humble bundled discovery server via fastdds discoery it works.

[devrite]

A workaround for my use case, which seems to work, is to start the dds discovery server externally bundled with ros and use a dds client in ddsrouter to connect to it. Using the current fast dds api would require some backports in rmw and some or backport rmw of rolling to humble.