1
|
|
|
<?php |
2
|
|
|
/** |
3
|
|
|
* Generator of database load balancing objects. |
4
|
|
|
* |
5
|
|
|
* This program is free software; you can redistribute it and/or modify |
6
|
|
|
* it under the terms of the GNU General Public License as published by |
7
|
|
|
* the Free Software Foundation; either version 2 of the License, or |
8
|
|
|
* (at your option) any later version. |
9
|
|
|
* |
10
|
|
|
* This program is distributed in the hope that it will be useful, |
11
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
12
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13
|
|
|
* GNU General Public License for more details. |
14
|
|
|
* |
15
|
|
|
* You should have received a copy of the GNU General Public License along |
16
|
|
|
* with this program; if not, write to the Free Software Foundation, Inc., |
17
|
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
18
|
|
|
* http://www.gnu.org/copyleft/gpl.html |
19
|
|
|
* |
20
|
|
|
* @file |
21
|
|
|
* @ingroup Database |
22
|
|
|
*/ |
23
|
|
|
|
24
|
|
|
/** |
25
|
|
|
* A simple single-master LBFactory that gets its configuration from the b/c globals |
26
|
|
|
*/ |
27
|
|
|
class LBFactorySimple extends LBFactory { |
28
|
|
|
/** @var LoadBalancer */ |
29
|
|
|
private $mainLB; |
30
|
|
|
/** @var LoadBalancer[] */ |
31
|
|
|
private $extLBs = []; |
32
|
|
|
|
33
|
|
|
/** @var array[] Map of (server index => server config) */ |
34
|
|
|
private $servers = []; |
35
|
|
|
/** @var array[] Map of (cluster => (server index => server config)) */ |
36
|
|
|
private $externalClusters = []; |
37
|
|
|
|
38
|
|
|
/** @var string */ |
39
|
|
|
private $loadMonitorClass; |
40
|
|
|
|
41
|
|
|
/** |
42
|
|
|
* @see LBFactory::__construct() |
43
|
|
|
* @param array $conf Parameters of LBFactory::__construct() as well as: |
44
|
|
|
* - servers : list of server configuration maps to Database::factory(). |
45
|
|
|
* Additionally, the server maps should have a 'load' key, which is used to decide |
46
|
|
|
* how often clients connect to one server verses the others. A 'max lag' key should |
47
|
|
|
* also be set on server maps, indicating how stale the data can be before the load |
48
|
|
|
* balancer tries to avoid using it. The map can have 'is static' set to disable blocking |
49
|
|
|
* replication sync checks (intended for archive servers with unchanging data). |
50
|
|
|
* - externalClusters : map of cluster names to server arrays. The servers arrays have the |
51
|
|
|
* same format as "servers" above. |
52
|
|
|
*/ |
53
|
|
|
public function __construct( array $conf ) { |
54
|
|
|
parent::__construct( $conf ); |
55
|
|
|
|
56
|
|
|
$this->servers = isset( $conf['servers'] ) ? $conf['servers'] : []; |
57
|
|
|
foreach ( $this->servers as $i => $server ) { |
58
|
|
|
if ( $i == 0 ) { |
59
|
|
|
$this->servers[$i]['master'] = true; |
60
|
|
|
} else { |
61
|
|
|
$this->servers[$i]['replica'] = true; |
62
|
|
|
} |
63
|
|
|
} |
64
|
|
|
|
65
|
|
|
$this->externalClusters = isset( $conf['externalClusters'] ) |
66
|
|
|
? $conf['externalClusters'] |
67
|
|
|
: []; |
68
|
|
|
$this->loadMonitorClass = isset( $conf['loadMonitorClass'] ) |
69
|
|
|
? $conf['loadMonitorClass'] |
70
|
|
|
: 'LoadMonitor'; |
71
|
|
|
} |
72
|
|
|
|
73
|
|
|
/** |
74
|
|
|
* @param bool|string $domain |
75
|
|
|
* @return LoadBalancer |
76
|
|
|
*/ |
77
|
|
|
public function newMainLB( $domain = false ) { |
78
|
|
|
return $this->newLoadBalancer( $this->servers ); |
79
|
|
|
} |
80
|
|
|
|
81
|
|
|
/** |
82
|
|
|
* @param bool|string $domain |
83
|
|
|
* @return LoadBalancer |
84
|
|
|
*/ |
85
|
|
|
public function getMainLB( $domain = false ) { |
86
|
|
|
if ( !isset( $this->mainLB ) ) { |
87
|
|
|
$this->mainLB = $this->newMainLB( $domain ); |
88
|
|
|
$this->getChronologyProtector()->initLB( $this->mainLB ); |
89
|
|
|
} |
90
|
|
|
|
91
|
|
|
return $this->mainLB; |
92
|
|
|
} |
93
|
|
|
|
94
|
|
|
public function newExternalLB( $cluster ) { |
95
|
|
|
if ( !isset( $this->externalClusters[$cluster] ) ) { |
96
|
|
|
throw new InvalidArgumentException( __METHOD__ . ": Unknown cluster \"$cluster\"." ); |
97
|
|
|
} |
98
|
|
|
|
99
|
|
|
return $this->newLoadBalancer( $this->externalClusters[$cluster] ); |
100
|
|
|
} |
101
|
|
|
|
102
|
|
View Code Duplication |
public function getExternalLB( $cluster ) { |
103
|
|
|
if ( !isset( $this->extLBs[$cluster] ) ) { |
104
|
|
|
$this->extLBs[$cluster] = $this->newExternalLB( $cluster ); |
105
|
|
|
$this->getChronologyProtector()->initLB( $this->extLBs[$cluster] ); |
106
|
|
|
} |
107
|
|
|
|
108
|
|
|
return $this->extLBs[$cluster]; |
109
|
|
|
} |
110
|
|
|
|
111
|
|
|
public function getAllMainLBs() { |
112
|
|
|
return [ 'DEFAULT' => $this->getMainLB() ]; |
113
|
|
|
} |
114
|
|
|
|
115
|
|
|
public function getAllExternalLBs() { |
116
|
|
|
$lbs = []; |
117
|
|
|
foreach ( $this->externalClusters as $cluster => $unused ) { |
118
|
|
|
$lbs[$cluster] = $this->getExternalLB( $cluster ); |
119
|
|
|
} |
120
|
|
|
|
121
|
|
|
return $lbs; |
122
|
|
|
} |
123
|
|
|
|
124
|
|
|
private function newLoadBalancer( array $servers ) { |
125
|
|
|
$lb = new LoadBalancer( array_merge( |
126
|
|
|
$this->baseLoadBalancerParams(), |
127
|
|
|
[ |
128
|
|
|
'servers' => $servers, |
129
|
|
|
'loadMonitor' => [ 'class' => $this->loadMonitorClass ], |
130
|
|
|
] |
131
|
|
|
) ); |
132
|
|
|
$this->initLoadBalancer( $lb ); |
133
|
|
|
|
134
|
|
|
return $lb; |
135
|
|
|
} |
136
|
|
|
|
137
|
|
|
/** |
138
|
|
|
* Execute a function for each tracked load balancer |
139
|
|
|
* The callback is called with the load balancer as the first parameter, |
140
|
|
|
* and $params passed as the subsequent parameters. |
141
|
|
|
* |
142
|
|
|
* @param callable $callback |
143
|
|
|
* @param array $params |
144
|
|
|
*/ |
145
|
|
|
public function forEachLB( $callback, array $params = [] ) { |
146
|
|
|
if ( isset( $this->mainLB ) ) { |
147
|
|
|
call_user_func_array( $callback, array_merge( [ $this->mainLB ], $params ) ); |
148
|
|
|
} |
149
|
|
|
foreach ( $this->extLBs as $lb ) { |
150
|
|
|
call_user_func_array( $callback, array_merge( [ $lb ], $params ) ); |
151
|
|
|
} |
152
|
|
|
} |
153
|
|
|
} |
154
|
|
|
|