private Consumer<Transition<State>> dieOnError(final Consumer<Transition<State>> closure) {
return transition -> {
try {
closure.accept(transition);
} catch (RuntimeException e) {
LOG.error("Caught unchecked exception: " + e, e);
stateMachine.transition(State.DEAD);
throw e;
}
};
}
@Override
public void onDefeated() {
LOG.error("Lost leadership, committing suicide.");
stateMachine.transition(State.DEAD);
}
@Override
public void onLeading(LeaderControl control) {
leaderControl.set(control);
stateMachine.transition(State.LEADER_AWAITING_REGISTRATION);
}
@Subscribe
public void registered(DriverRegistered event) {
stateMachine.transition(State.ACTIVE);
}
/**
* Prepares a scheduler to offer itself as a leader candidate. After this call the scheduler will
* host a live log replica and start syncing data from the leader via the log until it gets called
* upon to lead.
*
* @return A listener that can be offered for leadership of a distributed election.
*/
public LeadershipListener prepare() {
stateMachine.transition(State.PREPARING_STORAGE);
return leadershipListener;
}