nbully

An OTP application for leader election.

The nbully application starts a supervisor that supervises a worker process. This process runs in every node and consensuates node leadership with its homologues in other nodes.

Status

Prerequisites

Usage

In your rebar.config file, add the dependency:

{deps, [
    {nbully, {git, "git@github.com:nomasystems/nbully.git", {branch, "main"}}}
]}.

Then, once the application is started, you can consult nbully:leader/0 to know which node is the current leader. This value is the same for all nodes connected through net_kernel and might only change when nodes go up or down.

You can also use nbully:subscribe/0 to receive live updates when the leader changes in the form of a message {nbully_leader_update, Node}. For example:

ok = nbully:subscribe(),
InitialLeader = nbully:leader(),
% [...]
NewLeader =
  receive
    {nbully_leader_update, Node} -> Node
  after 1000 -> InitialLeader
end,
LeaderIsMe = node() =:= NewLeader,
% [...]
ok = nbully:unsubscribe().

Support

Any doubt or suggestion? Please, check out our issue tracker.

Contributing

Pull requests are welcome. Please read the contributing guidelines to know more about contribution.