anchor.diff:              %% synchronously.
               riak_core:register(riak_kv, [
                   {vnode_module, riak_kv_vnode},
  +                {health_check, {?MODULE, check_kv_health, []}},
                   {bucket_validator, riak_kv_bucket},
                   {stat_mod, riak_kv_stat}
               ]),
  
positive.code: 
  -behaviour(application).
  -export([start/2, prep_stop/1, stop/1]).
  
  -define(SERVICES, [{riak_kv_pb_object, 3, 6}, %% ClientID stuff
                     {riak_kv_pb_object, 9, 14}, %% Object requests
  
negative.code:                 "but your system says the epoch is ~p", [Epoch]),
              ok
      end.
  
  check_kv_health(_Pid) ->
      VNodes = riak_core_vnode_manager:all_index_pid(riak_kv_vnode),
      Threshold = app_helper:get_env(riak_kv, vnode_mailbox_limit, 5000),
      SlowVNs =
          [{Idx,Len} || {Idx, Pid} <- VNodes,
                        {message_queue_len, Len} <- process_info(Pid, [message_queue_len]),
                        Len > Threshold],
      SlowVNs =:= [].
  