anchor.diff: -%%%-------------------------------------------------------------------
  -%%% File    : riak_stat.erl
  -%%% Author  : Bryan Fink <bryan@basho.com>
  -%%% Description : Stats aggregator for Riak.
  -%%%
  -%%% Created : 10 Nov 2009 by Bryan Fink <bryan@basho.com>
  -%%%-------------------------------------------------------------------
  +%% This file is provided to you under the Apache License,
  +%% Version 2.0 (the "License"); you may not use this file
  +%% except in compliance with the License.  You may obtain
  +%% a copy of the License at
  +
  +%%   http://www.apache.org/licenses/LICENSE-2.0
  +
  +%% Unless required by applicable law or agreed to in writing,
  +%% software distributed under the License is distributed on an
  +%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  +%% KIND, either express or implied.  See the License for the
  +%% specific language governing permissions and limitations
  +%% under the License.    
  +
  +%% @doc riak_stat is a long-lived gen_server process for aggregating
  +%%      stats about the Riak node on which it is runing.
  +%%
  +%%      Update each stat with the exported function update/1.  Modify
  +%%      the internal function update/3 to add storage for new stats.
  +%%
  +%%      Get the latest aggregation of stats with the exported function
  +%%      get_stats/0.  Modify the internal function produce_stats/1 to
  +%%      change how stats are represented.
  +%%
  +%%      Current stats:
  +%%<dl><dt>  vnode_gets
  +%%</dt><dd> Total number of gets handled by all vnodes on this node
  +%%          in the last minute.
  +%%</dd><dd> update(vnode_get)
  +%%
  +%%</dd><dt> vnode_puts
  +%%</dt><dd> Total number of puts handled by all vnodes on this node
  +%%          in the last minute.
  +%%</dd><dd> update(vnode_put)
  +%%
  +%%</dd><dt> node_gets
  +%%</dt><dd> Number of gets coordinated by this node in the last
  +%%          minute.
  +%%</dd><dd> update({get_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_get_fsm_time_mean
  +%%</dt><dd> Mean time, in microseconds, between when a riak_get_fsm is
  +%%          started and when it sends a reply to the client, for the
  +%%          last minute.
  +%%</dd><dd> update({get_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_get_fsm_time_median
  +%%</dt><dd> Median time, in microseconds, between when a riak_get_fsm
  +%%          is started and when it sends a reply to the client, for
  +%%          the last minute.
  +%%</dd><dd> update({get_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_get_fsm_time_95
  +%%</dt><dd> Response time, in microseconds, met or beaten by 95% of
  +%%          riak_get_fsm executions.
  +%%</dd><dd> update({get_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_get_fsm_time_99
  +%%</dt><dd> Response time, in microseconds, met or beaten by 99% of
  +%%          riak_get_fsm executions.
  +%%</dd><dd> update({get_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_get_fsm_time_100
  +%%</dt><dd> Response time, in microseconds, met or beaten by 100% of
  +%%          riak_get_fsm executions.
  +%%</dd><dd> update({get_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_puts
  +%%</dt><dd> Number of puts coordinated by this node in the last
  +%%          minute.
  +%%</dd><dd> update({put_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_put_fsm_time_mean
  +%%</dt><dd> Mean time, in microseconds, between when a riak_put_fsm is
  +%%          started and when it sends a reply to the client, for the
  +%%          last minute.
  +%%</dd><dd> update({put_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_put_fsm_time_median
  +%%</dt><dd> Median time, in microseconds, between when a riak_put_fsm
  +%%          is started and when it sends a reply to the client, for
  +%%          the last minute.
  +%%</dd><dd> update({put_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_put_fsm_time_95
  +%%</dt><dd> Response time, in microseconds, met or beaten by 95% of
  +%%          riak_put_fsm executions.
  +%%</dd><dd> update({put_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_put_fsm_time_99
  +%%</dt><dd> Response time, in microseconds, met or beaten by 99% of
  +%%          riak_put_fsm executions.
  +%%</dd><dd> update({put_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> node_put_fsm_time_100
  +%%</dt><dd> Response time, in microseconds, met or beaten by 100% of
  +%%          riak_put_fsm executions.
  +%%</dd><dd> update({put_fsm_time, Microseconds})
  +%%
  +%%</dd><dt> cpu_nprocs
  +%%</dt><dd> Value returned by {@link cpu_sup:nprocs/0}.
  +%%
  +%%</dd><dt> cpu_avg1
  +%%</dt><dd> Value returned by {@link cpu_sup:avg1/0}.
  +%%
  +%%</dd><dt> cpu_avg5
  +%%</dt><dd> Value returned by {@link cpu_sup:avg5/0}.
  +%%
  +%%</dd><dt> cpu_avg15
  +%%</dt><dd> Value returned by {@link cpu_sup:avg15/0}.
  +%%
  +%%</dd><dt> mem_total
  +%%</dt><dd> The first element of the tuple returned by
  +%%          {@link memsup:get_memory_data/0}.
  +%%
  +%%</dd><dt> mem_allocated
  +%%</dt><dd> The second element of the tuple returned by
  +%%          {@link memsup:get_memory_data/0}.
  +%%
  +%%</dd><dt> disk
  +%%</dt><dd> Value returned by {@link disksup:get_disk_data/0}.
  +%%</dd></dl>
   -module(riak_stat).
   
   -behaviour(gen_server2).
  
positive.code:        mem_stats(),
         disk_stats()]).
  
  spiral_minute(Moment, Elt, State) ->
      Up = spiraltime:incr(0, Moment, element(Elt, State)),
      {_,Count} = spiraltime:rep_minute(Up),
      Count.
  
  slide_minute(Moment, Elt, State) ->
      {Count, Mean} = slide:mean(element(Elt, State), Moment),
      {_, Nines} = slide:nines(element(Elt, State), Moment),
      {Count, Mean, Nines}.
  
  vnode_stats(Moment, State) ->
      [{F, spiral_minute(Moment, Elt, State)}
       || {F, Elt} <- [{vnode_gets, #state.vnode_gets},
                       {vnode_puts, #state.vnode_puts}]].
  
  node_stats(Moment, State) ->
      {Gets, GetMean, {GetMedian, GetNF, GetNN, GetH}} =
          slide_minute(Moment, #state.get_fsm_time, State),
  
negative.code: %%% Internal functions
  %%--------------------------------------------------------------------
  
  %% @spec update(Stat::term(), integer(), state()) -> state()
  %% @doc Update the given stat in State, returning a new State.
  update(vnode_get, Moment, State) ->
      spiral_incr(#state.vnode_gets, Moment, State);
  update(vnode_put, Moment, State) ->
  