Merge pull request #7 from mondemand/max_metrics

Moved max_metrics constant to mondemand_config

ChangeLog

@@ -1,3 +1,6 @@
+Version 6.2.1 (whalen)
+  * moved max_metrics constant to mondemand_config so we can tweak at runtime
+
 Version 6.2.0 (molinaro)
   * added a function to convert from millis since epoch to erlang:now/0
   format

include/mondemand.hrl

@@ -39,7 +39,6 @@
 
 % related to stats messages
 -define (MD_STATS_EVENT, <<"MonDemand::StatsMsg">>).
--define (MD_MAX_METRICS, 1024).
 
 % internal records for MonDemand::StatsMsg
 -record (md_stats_msg, { send_time,

src/mondemand.app.src

@@ -1,7 +1,7 @@
 { application, mondemand,
   [
    { description, "Erlang Mondemand Bindings." },
-   { vsn, "6.2.0" },
+   { vsn, "6.2.1" },
    { modules, [] },
    { registered, [mondemand,mondemand_sup]},
    { applications, [kernel,stdlib,syntax_tools,lwes]},

src/mondemand_config.erl

@@ -23,13 +23,16 @@
            default_stats/0,
            lwes_config/0,
            minutes_to_keep/0,
+           max_metrics/0,
            parse_config/1
          ]).
 
 -define (DEFAULT_MAX_SAMPLE_SIZE, 10).
 -define (DEFAULT_STATS, [min, max, sum, count]).
 -define (DEFAULT_MINUTES_TO_KEEP, 10).
 -define (MOCHI_SENDER_HOST, mondemand_sender_host_global).
+-define (MOCHI_MAX_METRICS, mondemand_max_metrics_global).
+-define (DEFAULT_MAX_METRICS, 512).
 
 % this function is meant to be called before the supervisor and
 % pulls all those configs which are mostly static.
@@ -39,7 +42,13 @@ init () ->
       undefined -> net_adm:localhost();
       {ok, H} -> H
     end,
-  mondemand_global:put (?MOCHI_SENDER_HOST, Host).
+  mondemand_global:put (?MOCHI_SENDER_HOST, Host),
+  MaxMetrics =
+    case application:get_env (mondemand, max_metrics) of
+      undefined -> ?DEFAULT_MAX_METRICS;
+      {ok, M} -> M
+    end,
+  mondemand_global:put (?MOCHI_MAX_METRICS, MaxMetrics).
 
 host () ->
   mondemand_global:get (?MOCHI_SENDER_HOST).
@@ -237,6 +246,9 @@ minutes_to_keep () ->
     {ok, I} when is_integer (I) -> I
   end.
 
+max_metrics () ->
+ mondemand_global:get (?MOCHI_MAX_METRICS).
+
 %%--------------------------------------------------------------------
 %%% Test functions
 %%--------------------------------------------------------------------

src/mondemand_statsmsg.erl

@@ -217,12 +217,17 @@ from_lwes (#lwes_event { attrs = Data}) ->
   }.
 
 to_lwes (L) when is_list (L) ->
-  lists:flatten (lists:map (fun to_lwes/1, L) );
+  MaxMetrics = mondemand_config:max_metrics (),
+  lists:flatten (lists:map (fun (X) -> to_lwes (X, MaxMetrics) end, L) );
 
-% split events into chunks of MD_MAX_METRICS
-to_lwes (MondemandStatsMsg = #md_stats_msg { num_metrics = NumMetrics })
-  when NumMetrics > ?MD_MAX_METRICS ->
-  lists:reverse (to_lwes( MondemandStatsMsg, []));
+to_lwes (MondemandStatsMsg = #md_stats_msg {}) ->
+  MaxMetrics = mondemand_config:max_metrics (),
+  to_lwes (MondemandStatsMsg, MaxMetrics).
+
+% split events into chunks of max_metrics
+to_lwes (MondemandStatsMsg = #md_stats_msg { num_metrics = NumMetrics }, MaxMetrics)
+  when NumMetrics > MaxMetrics  ->
+  lists:reverse (to_lwes( MondemandStatsMsg, MaxMetrics, []));
 
 to_lwes (#md_stats_msg { send_time = SendTimeIn,
                          collect_time = CollectTimeIn,
@@ -232,7 +237,7 @@ to_lwes (#md_stats_msg { send_time = SendTimeIn,
                          context = Context,
                          num_metrics = NumMetrics,
                          metrics = Metrics
-                       }) ->
+                       }, _) ->
   NowMillis = mondemand_util:millis_since_epoch(),
   SendTime =
     case SendTimeIn of
@@ -262,18 +267,19 @@ to_lwes (#md_stats_msg { send_time = SendTimeIn,
 to_lwes (MondemandStatsMsg = #md_stats_msg {
                          num_metrics = NumMetrics,
                          metrics = Metrics
-                       }, EventList)
-  when NumMetrics > ?MD_MAX_METRICS ->
-  { HeadMetrics, TailMetrics } = lists:split (?MD_MAX_METRICS, Metrics),
+                       }, MaxMetrics, EventList)
+  when NumMetrics > MaxMetrics ->
+  { HeadMetrics, TailMetrics } = lists:split (MaxMetrics, Metrics),
   to_lwes (MondemandStatsMsg#md_stats_msg {
                               num_metrics = length (TailMetrics),
                               metrics = TailMetrics },
+           MaxMetrics,
            [ to_lwes (MondemandStatsMsg#md_stats_msg {
-                                         num_metrics = ?MD_MAX_METRICS,
+                                         num_metrics = MaxMetrics,
                                          metrics = HeadMetrics})
               | EventList ]);
 
-to_lwes (MondemandStatsMsg = #md_stats_msg {}, EventList) ->
+to_lwes (MondemandStatsMsg = #md_stats_msg {}, _, EventList) ->
   [ to_lwes (MondemandStatsMsg) | EventList ].
 
 metric_to_lwes (MetricIndex,
@@ -2035,8 +2041,10 @@ statsmsg_test_ () ->
     },
     { "many metrics",
       fun() ->
+        mondemand_config:init(),
         C = [{<<"foo">>,<<"bar">>}],
-        MetricsCount = ?MD_MAX_METRICS + 1,
+        MaxMetrics = mondemand_config:max_metrics (),
+        MetricsCount = MaxMetrics + 1,
         E2K0Name = list_to_binary(string:concat("baz", integer_to_list(MetricsCount))),
         MIn = lists:map(fun(X) ->
                           {
@@ -2056,7 +2064,7 @@ statsmsg_test_ () ->
         % test that to_lwes of long statsmsg  returns several events that are correct
         [E1, E2] = to_lwes(S),
         % test that the metric counts and first metric in events match expected values
-        ?assert (lists:member({?LWES_U_INT_16, <<"num">>, ?MD_MAX_METRICS}, E1#lwes_event.attrs)),
+        ?assert (lists:member({?LWES_U_INT_16, <<"num">>, MaxMetrics}, E1#lwes_event.attrs)),
         ?assert (lists:member({?LWES_STRING, <<"k0">>, <<"baz1">>}, E1#lwes_event.attrs)),
         ?assert (lists:member({?LWES_STRING, <<"t0">>, <<"gauge">>}, E1#lwes_event.attrs)),
         ?assert (lists:member({?LWES_INT_64, <<"v0">>, 1}, E1#lwes_event.attrs)),