anchor.diff:  
   -module(riak_core_dist_mon).
   
  --export([start_link/0, set_dist_buf_sizes/2]).
  +-export([start_link/0, set_dist_buf_sizes/2, get_riak_env_vars/0]).
   
   %% gen_server callbacks
   -behavior(gen_server).
   -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
            terminate/2, code_change/3]).
   
  --record(state, {}).
  +-record(state, {
  +          sndbuf :: non_neg_integer(),
  +          recbuf :: non_neg_integer()
  +         }).
   
   %% provided for testing convenience and debugging.
   set_dist_buf_sizes(SendSz, RecvSz) 
  
positive.code:     %% register for monitor events so we can adjust buffers on 
      %% new connections when they're started.
      ok = net_kernel:monitor_nodes(true, [{node_type, visible}, nodedown_reason]),
      DistCtrl = erlang:system_info(dist_ctrl),
      %% make sure that buffers are correct on existing connections.
      [set_port_buffers(Port)
       || {_Node, Port} <- DistCtrl],
      {ok, #state{}}.
  
  
  
  handle_call({set_dist_buf_sizes, SendSz, RecvSz}, _From, State) ->
      Reply = 
          [inet:setopts(Port, [{sndbuf, SendSz}, {recbuf, RecvSz}])
           || {_Node, Port} <- erlang:system_info(dist_ctrl)],
      {reply, Reply, State};
  handle_call(Msg, _From, State) ->
      lager:warning("unknown call message received: ~p", [Msg]),
      {noreply, State}.
  
negative.code: 
  %% private 
  
  set_port_buffers(Port, SendBufSz, RecBufSz) ->
      inet:setopts(Port, [{sndbuf, SendBufSz},
                          {recbuf, RecBufSz}]).
  