Librecast

Librecast is an experimental communication daemon intending to to provide fast, efficient and scalable communication between servers by leveraging IPv6 multicast.

NB: this is a WORK IN PROGRESS and is INCOMPLETE.

Features:

  • IPv6 and multicast supported from the outset
  • light, fast and simple design
  • scalability a design consideration from the outset

Intended to be used called from client libraries to make scalable, secure network programming available easily in any supported language. Initial support will be for C, with python, perl and other wrappers following as time and interest permits.

At the core of the design is the concept of fetching variables remotely from one or more network nodes and acting on the results programmatically. This makes writing, say, monitoring or configuration management logic simple in any supported language.

Essentially this enables us to utilise the actor model of distributed programming, backed by the advantages of IPv6 multicast by default, and degrading gracefully through a series of fallback options to improve reachability in cases where the default mode is unavailable.

There are plenty of other tools available for monitoring, configuration management etc and several network programming frameworks. However, IPv6 is often an afterthought, if it is supported at all. Multicast is rarely used, even when communicating one to many. Often heavyweight unicast TCP connections are established to communicate the same information to many servers simultaenously. Security is sometimes considered an optional extra. Some are built in higher level languages I'm not fond of, and which I feel have little place in low-level systems programming. Perhaps I'm just getting grumpier as I get older.

Anyway, I thought it would be interesting to build something from scratch and see whether this approach has any merit. I'll put this out there in case anyone else finds it useful. Comments, questions, suggestions, bug reports, and patches all welcome.

2016-11-21