4.1.32 on_membership_change(Hook, Prio) ¶

-spec on_membership_change(fun((cluster_id(),
                                _Local :: site(),
                                _Remote :: site(),
                                _IsMember ::
                                    boolean()) -> _),
                           classy_hook:conf()) -> classy_hook:hook().

Register a hook that is executed when a site joins or leaves a cluster.

Note: this hook can be executed multiple times if the local node is abruptly stopped while the hooks are running. If the remote site re-joins the cluster while the local was down, the hook may or may not run.