Requests for discussion

One of the exciting challenges of being an all open source company is figuring out how to get design conversations out of the lunch time discussion and the private IRC/Jabber/Slack channels and into the broader community. There are many different approaches to this, and the most obvious one is to simply use whatever is used for issue tracking. Issue trackers don’t really fit the job, however: they don’t allow for threading; they don’t really allow for holistic discussion; they’re not easily connected with a single artifact in the repository, etc. In short, even on projects with modest activity, using issue tracking for design discussions causes the design discussions to be drowned out by the defects of the day – and on projects with more intense activity, it’s total mayhem.

So if issue tracking doesn’t fit, what’s the right way to have an open source design discussion? Back in the day at Sun, we had the Software Development Framework (SDF), which was a decidedly mixed bag. While it was putatively shrink-to-fit, in practice it felt too much like a bureaucratic hurdle with concomitant committees and votes and so on – and it rarely yielded productive design discussion. That said, we did like the artifacts that it produced, and even today in the illumos community we find that we go back to the Platform Software Architecture Review Committee (PSARC) archives to understand why things were done a particular way. (If you’re looking for some PSARC greatest hits, check out PSARC 2002/174 on zones, PSARC 2002/188 on least privilege or PSARC 2005/471 on branded zones.)

In my experience, the best part of the SDF was also the most elemental: it forced things to be written down in a forum reserved for architectural discussions, which alone forced some basic clarity on what was being built and why. At Joyent, we have wanted to capture this best element of the SDF without crippling ourselves with process – and in particular, we have wanted to allow engineers to write down their thinking while it is still nascent, such that it can be discussed when there is still time to meaningfully change it! This thinking, as it turns out, is remarkably close to the original design intent of the IETF’s Request for Comments, as expressed in RFC 3:

The content of a note may be any thought, suggestion, etc. related to the software or other aspect of the network. Notes are encouraged to be timely rather than polished. Philosophical positions without examples or other specifics, specific suggestions or implementation techniques without introductory or background explication, and explicit questions without any attempted answers are all acceptable. The minimum length for a note is one sentence.

These standards (or lack of them) are stated explicitly for two reasons. First, there is a tendency to view a written statement as ipso facto authoritative, and we hope to promote the exchange and discussion of considerably less than authoritative ideas. Second, there is a natural hesitancy to publish something unpolished, and we hope to ease this inhibition.

We aren’t the only ones to be inspired by the IETF’s venerable RFCs, and the language communities in particular seem to be good at this: Java has Java Specification Requests, Python has Python Enhancement Proposals, Perl has the (oddly named) Perl 6 apocalypses, and Rust has Rust RFCs. But the other systems software communities have been nowhere near as structured about their design discussions, and you are hard-pressed to find similar constructs for operating systems, databases, container management systems, etc.

Encouraged by what we’ve seen by the language communities, we wanted to introduce RFCs for the open source system software that we lead – but because we deal so frequently with RFCs in the IETF context, we wanted to avoid the term “RFC” itself: IETF RFCs tend to be much more formalized than the original spirit, and tend to describe an agreed-upon protocol rather than nascent ideas. So to avoid confusion with RFCs while still capturing some of what they were trying to solve, we have started a Requests for Discussion (RFD) repository for the open source projects that we lead. We will announce an RFD on the mailing list that serves the community (e.g., sdc-discuss) to host the actual discussion, with a link to the corresponding directory in the repo that will host artifacts from the discussion. We intend to kick off RFDs for the obvious things like adding new endpoints, adding new commands, adding new services, changing the behavior of endpoints and commands, etc. – but also for the less well-defined stuff that captures earlier thinking.

Finally, for the RFD that finally got us off the mark on doing this, see RFD 1: Triton Container Naming Service. Discussion very much welcome!