Faasm Collective Communication

This two-tier architecture is flexible and works well for a range of applications. Synchronisationbetween the local tier and the global tier is crucial in enabling this flexibility, but doesintroduce latency and network overheads. Certain classes of applications have well defined patternsfor sharing data, and don't require this much flexibility. Accordingly, we can introduce optimisationsin Faasm's state management specifically for such applications, hence avoiding unnecessary overheads incertain cases.

To do this, Faasm uses point-to-point replication. This is a special type of state synchronisationthat occurs only through the local tier of each host, and does not involve the global tier.

If many functions on a given host need to access the same data, only one point-to-point replication is requiredto ensure they all have access.

Collective operations

TODO - finish these notes