Sizigy is a pet project born as a way to renew a bit of knowledge of the low level programming in C. It's an MQTT message broker built upon epoll interface, aiming to guarantee exactly once semantic. Distribution is still in development as well as a lot of the core features, but it is already possible to play with it. It's a good exercise to explore and better understand the TCP stack, endianness, serialization and scalability.
TBD.
Basically it's an epoll server, when the system starts the main thread create an epoll file descriptor and share it among a pool of workers, EPOLLONESHOT flag allow the wake up of just one thread per event, and the kernel takes all the responsibility of events handling. For the distribution part it creates a separate epoll instance, used by a dedicated thread which manage the communication with other peers. Each thread handle incoming data from a connection by using a dedicated ring buffer, this way it is possible to avoid loss of data by the MTU limit in case of huge data payloads.
TBD.
See the CHANGELOG file.