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:     end,
      gen_server2:start_link({local, ?MODULE}, ?MODULE, [], []).
  
  get_stats() ->
      gen_server2:call(?MODULE, get_stats).
  
  update(Stat) ->
      gen_server2:cast(?MODULE, {update, Stat, riak_util:moment()}).
  
  %%====================================================================
  %% gen_server callbacks
  %%====================================================================
  
  %%--------------------------------------------------------------------
  %% Function: init(Args) -> {ok, State} |
  %%                         {ok, State, Timeout} |
  %%                         ignore               |
  %%                         {stop, Reason}
  %% Description: Initiates the server
  %%--------------------------------------------------------------------
  init([]) ->
      {ok, #state{vnode_gets=spiraltime:fresh(),
                  vnode_puts=spiraltime:fresh(),
                  get_fsm_time=slide:fresh(),
                  put_fsm_time=slide:fresh()}}.
  
  %%--------------------------------------------------------------------
  %% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
  %%                                      {reply, Reply, State, Timeout} |
  %%                                      {noreply, State} |
  %%                                      {noreply, State, Timeout} |
  %%                                      {stop, Reason, Reply, State} |
  %%                                      {stop, Reason, State}
  %% Description: Handling call messages
  %%--------------------------------------------------------------------
  handle_call(get_stats, _From, State) ->
      {reply, produce_stats(State), State};
  handle_call(_Request, _From, State) ->
      Reply = ok,
      {reply, Reply, State}.
  
  %%--------------------------------------------------------------------
  %% Function: handle_cast(Msg, State) -> {noreply, State} |
  %%                                      {noreply, State, Timeout} |
  %%                                      {stop, Reason, State}
  %% Description: Handling cast messages
  %%--------------------------------------------------------------------
  handle_cast({update, Stat, Moment}, State) ->
      {noreply, update(Stat, Moment, State)};
  handle_cast(_Msg, State) ->
      {noreply, State}.
  
  %%--------------------------------------------------------------------
  %% Function: handle_info(Info, State) -> {noreply, State} |
  %%                                       {noreply, State, Timeout} |
  %%                                       {stop, Reason, State}
  %% Description: Handling all non call/cast messages
  %%--------------------------------------------------------------------
  handle_info(_Info, State) ->
      {noreply, State}.
  
  %%--------------------------------------------------------------------
  %% Function: terminate(Reason, State) -> void()
  %% Description: This function is called by a gen_server when it is about to
  %% terminate. It should be the opposite of Module:init/1 and do any necessary
  %% cleaning up. When it returns, the gen_server terminates with Reason.
  %% The return value is ignored.
  %%--------------------------------------------------------------------
  terminate(_Reason, _State) ->
      ok.
  
  %%--------------------------------------------------------------------
  %% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
  %% Description: Convert process state when code is changed
  %%--------------------------------------------------------------------
  code_change(_OldVsn, State, _Extra) ->
      {ok, State}.
  
  
negative.code: -record(state,{vnode_gets,vnode_puts,
                 get_fsm_time,put_fsm_time}).
  
  %% @spec start_link() -> {ok,Pid} | ignore | {error,Error}
  %% @doc Start the server.  Also start the os_mon application, if it's
  %%      not already running.
  start_link() ->
      case application:start(os_mon) of
          ok -> ok;
  