Preview new claim

gistfile1.erl

Compute_Next = fun(Ring1,Ring2) ->
    Owners1 = riak_core_ring:all_owners(Ring1),
    Owners2 = riak_core_ring:all_owners(Ring2),
    Owners3 = lists:zip(Owners1, Owners2),
    [{Idx, PrevOwner, NewOwner, [], awaiting}
            || {{Idx, PrevOwner}, {Idx, NewOwner}} <- Owners3,
              PrevOwner /= NewOwner]
end.

N = app_helper:get_env(riak_core,target_n_val,4),
{ok,Ring}= riak_core_ring_manager:get_my_ring(),
NewRing = riak_core_claim:claim(Ring,{riak_core_claim,wants_claim_v3},{riak_core_claim,choose_claim_v3}),
Next = Compute_Next(Ring,NewRing),
io:format("Initial Ring:~n~p~n",[riak_core_claim_util:ring_stats(Ring,N)]),
io:format("After ~p ownership changes:~n~p~n",[length(Next),riak_core_claim_util:ring_stats(NewRing,N)]).