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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mod_proxy.h"
#include "scoreboard.h"
#include "ap_mpm.h"
#include "apr_version.h"
#include "apr_hooks.h"
module AP_MODULE_DECLARE_DATA lbmethod_bybusyness_module;
static proxy_worker *find_best_bybusyness(proxy_balancer *balancer,
request_rec *r)
{
int i;
proxy_worker **worker;
proxy_worker *mycandidate = NULL;
int cur_lbset = 0;
int max_lbset = 0;
int checking_standby;
int checked_standby;
int total_factor = 0;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy: Entering bybusyness for BALANCER (%s)",
balancer->name);
/* First try to see if we have available candidate */
do {
checking_standby = checked_standby = 0;
while (!mycandidate && !checked_standby) {
worker = (proxy_worker **)balancer->workers->elts;
for (i = 0; i < balancer->workers->nelts; i++, worker++) {
if (!checking_standby) { /* first time through */
if ((*worker)->s->lbset > max_lbset)
max_lbset = (*worker)->s->lbset;
}
if ((*worker)->s->lbset != cur_lbset)
continue;
if ( (checking_standby ? !PROXY_WORKER_IS_STANDBY(*worker) : PROXY_WORKER_IS_STANDBY(*worker)) )
continue;
/* If the worker is in error state run
* retry on that worker. It will be marked as
* operational if the retry timeout is elapsed.
* The worker might still be unusable, but we try
* anyway.
*/
if (!PROXY_WORKER_IS_USABLE(*worker))
ap_proxy_retry_worker("BALANCER", *worker, r->server);
/* Take into calculation only the workers that are
* not in error state or not disabled.
*/
if (PROXY_WORKER_IS_USABLE(*worker)) {
(*worker)->s->lbstatus += (*worker)->s->lbfactor;
total_factor += (*worker)->s->lbfactor;
if (!mycandidate
|| (*worker)->s->busy < mycandidate->s->busy
|| ((*worker)->s->busy == mycandidate->s->busy && (*worker)->s->lbstatus > mycandidate->s->lbstatus))
mycandidate = *worker;
}
}
checked_standby = checking_standby++;
}
cur_lbset++;
} while (cur_lbset <= max_lbset && !mycandidate);
if (mycandidate) {
mycandidate->s->lbstatus -= total_factor;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy: bybusyness selected worker \"%s\" : busy %" APR_SIZE_T_FMT " : lbstatus %d",
mycandidate->name, mycandidate->s->busy, mycandidate->s->lbstatus);
}
return mycandidate;
}
static apr_status_t reset(proxy_balancer *balancer, request_rec *r) {
return APR_SUCCESS;
}
static apr_status_t age(proxy_balancer *balancer, request_rec *r) {
return APR_SUCCESS;
}
static const proxy_balancer_method bybusyness =
{
"bybusyness",
&find_best_bybusyness,
&reset,
&age,
NULL
};
static void register_hook(apr_pool_t *p)
{
ap_register_provider(p, PROXY_LBMETHOD, "bybusyness", "0", &bybusyness);
}
module AP_MODULE_DECLARE_DATA lbmethod_bybusyness_module = {
STANDARD20_MODULE_STUFF,
NULL, /* create per-directory config structure */
NULL, /* merge per-directory config structures */
NULL, /* create per-server config structure */
NULL, /* merge per-server config structures */
NULL, /* command apr_table_t */
register_hook /* register hooks */
};
|
