Legion is framework for building clusters of homogenous nodes that must maintain a shared, replicated state.
For instance, maybe in order to scale a service you are using a partitioning strategy to direct traffic for users A-H to node 1, users I-Q to node 2, and R-Z to node 3. The partition table itself is something all the nodes have to agree on and would make an excellent candidate for the "shared, replicated state" managed by this framework.
To update the shared state, whatever it is, use:
applyFast- or
applyConsistent
Additionally, since Legion already has to understand about different nodes in the cluster, and how to talk to them, we provide a variety of tools to help facilitate inter-node communication:
-
cast: We support sending arbitrary messages to other peers without waiting on a response. -
call: We support sending requests to other peers that block on a response. -
broadcast: We support sending a message to every other peer without waiting on a response -
broadcall: We support sending a request to every other peer, and blocking until we recieve a response from them all.