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
|
%% 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_load).
-export([local_load/0, remote_loads/0, pick/0]).
-define(FUDGE_FACTOR, 0.98).
-define(TIMEOUT, 100).
%%----------------------------------------------------------------------------
-ifdef(use_specs).
-type(erlang_node() :: atom()).
-type(load() :: {{non_neg_integer(), float()}, erlang_node()}).
-spec(local_load/0 :: () -> load()).
-spec(remote_loads/0 :: () -> [load()]).
-spec(pick/0 :: () -> erlang_node()).
-endif.
%%----------------------------------------------------------------------------
local_load() ->
LoadAvg = case whereis(cpu_sup) of
undefined -> 0.0;
_Other -> cpu_sup:avg1()
end,
{{statistics(run_queue), LoadAvg}, node()}.
remote_loads() ->
{ResL, _BadNodes} =
rpc:multicall(nodes(), ?MODULE, local_load, [], ?TIMEOUT),
ResL.
pick() ->
RemoteLoads = remote_loads(),
{{RunQ, LoadAvg}, Node} = local_load(),
%% add bias towards current node
AdjustedLoadAvg = LoadAvg * ?FUDGE_FACTOR,
Loads = [{{RunQ, AdjustedLoadAvg}, Node} | RemoteLoads],
{_, SelectedNode} = lists:min(Loads),
SelectedNode.
|
