1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
%% The contents of this file are subject to the Mozilla Public License
%% Version 1.1 (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.mozilla.org/MPL/
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
%% License for the specific language governing rights and limitations
%% under the License.
%%
%% The Original Code is RabbitMQ.
%%
%% The Initial Developers of the Original Code are LShift Ltd.,
%% Cohesive Financial Technologies LLC., and Rabbit Technologies Ltd.
%%
%% Portions created by LShift Ltd., Cohesive Financial Technologies
%% LLC., and Rabbit Technologies Ltd. are Copyright (C) 2007-2008
%% LShift Ltd., Cohesive Financial Technologies LLC., and Rabbit
%% Technologies Ltd.;
%%
%% All Rights Reserved.
%%
%% Contributor(s): ______________________________________.
%%
-module(rabbit_alarm).
-behaviour(gen_event).
-export([start/0, stop/0]).
-export([init/1, handle_call/2, handle_event/2, handle_info/2,
terminate/2, code_change/3]).
-define(MEMSUP_CHECK_INTERVAL, 1000).
-record(alarms, {system_memory_high_watermark = false}).
%%----------------------------------------------------------------------------
-ifdef(use_specs).
-spec(start/0 :: () -> 'ok').
-spec(stop/0 :: () -> 'ok').
-endif.
%%----------------------------------------------------------------------------
start() ->
%% 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),
ok = alarm_handler:add_alarm_handler(?MODULE).
stop() ->
ok = alarm_handler:delete_alarm_handler(?MODULE).
%%----------------------------------------------------------------------------
init([]) ->
{ok, #alarms{}}.
handle_call(_Request, State) ->
{ok, not_understood, State}.
handle_event({set_alarm, {system_memory_high_watermark, []}}, State) ->
{ok, State#alarms{system_memory_high_watermark = true}};
handle_event({clear_alarm, system_memory_high_watermark}, State) ->
{ok, State#alarms{system_memory_high_watermark = false}};
handle_event(_Event, State) ->
{ok, State}.
handle_info(_Info, State) ->
{ok, State}.
terminate(_Arg, _State) ->
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
|
