new memsup code

1 files changed, 12 insertions, 89 deletions

diff --git a/src/rabbit_alarm.erl b/src/rabbit_alarm.erl
index 309c9a0e..c1997554 100644
--- a/src/rabbit_alarm.erl
+++ b/src/rabbit_alarm.erl
@@ -33,24 +33,19 @@
 
 -behaviour(gen_event).
 
--export([start/1, stop/0, register/2]).
+-export([start/0, stop/0, register/2]).
 
 -export([init/1, handle_call/2, handle_event/2, handle_info/2,
          terminate/2, code_change/3]).
 
--define(MEMSUP_CHECK_INTERVAL, 1000).
-
-%% OSes on which we know memory alarms to be trustworthy
--define(SUPPORTED_OS, [{unix, linux}, {unix, darwin}]).
-
--record(alarms, {alertees, system_memory_high_watermark = false}).
+-record(alarms, {alertees, memory_high_watermark = false}).
 
 %%----------------------------------------------------------------------------
 
 -ifdef(use_specs).
 
 -type(mfa_tuple() :: {atom(), atom(), list()}).
--spec(start/1 :: (bool() | 'auto') -> 'ok').
+-spec(start/0 :: () -> 'ok').
 -spec(stop/0 :: () -> 'ok').
 -spec(register/2 :: (pid(), mfa_tuple()) -> 'ok').
 
@@ -58,20 +53,8 @@
 
 %%----------------------------------------------------------------------------
 
-start(MemoryAlarms) ->
-    EnableAlarms = case MemoryAlarms of
-                       true  -> true;
-                       false -> false;
-                       auto  -> lists:member(os:type(), ?SUPPORTED_OS)
-                   end,
-    ok = alarm_handler:add_alarm_handler(?MODULE, [EnableAlarms]),
-    case whereis(memsup) of
-        undefined -> if EnableAlarms -> ok = start_memsup(),
-                                        ok = adjust_memsup_interval();
-                        true         -> ok
-                     end;
-        _         -> ok = adjust_memsup_interval()
-    end.
+start() ->
+    ok = alarm_handler:add_alarm_handler(?MODULE, []).
 
 stop() ->
     ok = alarm_handler:delete_alarm_handler(?MODULE).
@@ -83,19 +66,13 @@ register(Pid, HighMemMFA) ->
 
 %%----------------------------------------------------------------------------
 
-init([MemoryAlarms]) ->
-    {ok, #alarms{alertees = case MemoryAlarms of
-                                true  -> dict:new();
-                                false -> undefined
-                            end}}.
+init([]) ->
+    {ok, #alarms{alertees = dict:new()}}.
 
-handle_call({register, _Pid, _HighMemMFA},
-            State = #alarms{alertees = undefined}) ->
-    {ok, ok, State};
 handle_call({register, Pid, HighMemMFA},
             State = #alarms{alertees = Alertess}) ->
     _MRef = erlang:monitor(process, Pid),
-    case State#alarms.system_memory_high_watermark of
+    case State#alarms.memory_high_watermark of
         true  -> {M, F, A} = HighMemMFA,
                  ok = erlang:apply(M, F, A ++ [Pid, true]);
         false -> ok
@@ -106,20 +83,17 @@ handle_call({register, Pid, HighMemMFA},
 handle_call(_Request, State) ->
     {ok, not_understood, State}.
 
-handle_event({set_alarm, {system_memory_high_watermark, []}}, State) ->
+handle_event({set_alarm, {memory_high_watermark, []}}, State) ->
     ok = alert(true, State#alarms.alertees),
-    {ok, State#alarms{system_memory_high_watermark = true}};
+    {ok, State#alarms{memory_high_watermark = true}};
 
-handle_event({clear_alarm, system_memory_high_watermark}, State) ->
+handle_event({clear_alarm, memory_high_watermark}, State) ->
     ok = alert(false, State#alarms.alertees),
-    {ok, State#alarms{system_memory_high_watermark = false}};
+    {ok, State#alarms{memory_high_watermark = false}};
 
 handle_event(_Event, State) ->
     {ok, State}.
 
-handle_info({'DOWN', _MRef, process, _Pid, _Reason},
-            State = #alarms{alertees = undefined}) ->
-    {ok, State};
 handle_info({'DOWN', _MRef, process, Pid, _Reason},
             State = #alarms{alertees = Alertess}) ->
     {ok, State#alarms{alertees = dict:erase(Pid, Alertess)}};
@@ -134,57 +108,6 @@ code_change(_OldVsn, State, _Extra) ->
     {ok, State}.
 
 %%----------------------------------------------------------------------------
-
-start_memsup() ->
-    {Mod, Args} =
-        case os:type() of
-            %% memsup doesn't take account of buffers or cache when
-            %% considering "free" memory - therefore on Linux we can
-            %% get memory alarms very easily without any pressure
-            %% existing on memory at all. Therefore we need to use
-            %% our own simple memory monitor.
-            %%
-            {unix, linux}  -> {rabbit_memsup, [rabbit_memsup_linux]};
-            {unix, darwin} -> {rabbit_memsup, [rabbit_memsup_darwin]};
-
-            %% Start memsup programmatically rather than via the
-            %% rabbitmq-server script. This is not quite the right
-            %% thing to do as os_mon checks to see if memsup is
-            %% available before starting it, but as memsup is
-            %% available everywhere (even on VXWorks) it should be
-            %% ok.
-            %%
-            %% One benefit of the programmatic startup is that we
-            %% can add our alarm_handler before memsup is running,
-            %% thus ensuring that we notice memory alarms that go
-            %% off on startup.
-            %%
-            _              -> {memsup, []}
-        end,
-    %% This is based on os_mon:childspec(memsup, true)
-    {ok, _} = supervisor:start_child(
-                os_mon_sup,
-                {memsup, {Mod, start_link, Args},
-                 permanent, 2000, worker, [Mod]}),
-    ok.
-
-adjust_memsup_interval() ->
-    %% The default memsup check interval is 1 minute, which is way too
-    %% long - rabbit can gobble up all memory in a matter of seconds.
-    %% Unfortunately the memory_check_interval configuration parameter
-    %% and memsup:set_check_interval/1 function only provide a
-    %% granularity of minutes. So we have to peel off one layer of the
-    %% API to get to the underlying layer which operates at the
-    %% granularity of milliseconds.
-    %%
-    %% Note that the new setting will only take effect after the first
-    %% check has completed, i.e. after one minute. So if rabbit eats
-    %% all the memory within the first minute after startup then we
-    %% are out of luck.
-    ok = os_mon:call(memsup,
-                     {set_check_interval, ?MEMSUP_CHECK_INTERVAL},
-                     infinity).
-
 alert(_Alert, undefined) ->
     ok;
 alert(Alert, Alertees) ->