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comparison src/http/modules/ngx_http_degradation_module.c @ 665:0b460e61bdcd default tip

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Merge with nginx 1.0.0.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 25 Apr 2011 04:22:17 +0400
parents 428c6e58046a
children
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572:06419a2298a9 665:0b460e61bdcd
1
2 /*
3 * Copyright (C) Igor Sysoev
4 */
5
6
7 #include <ngx_config.h>
8 #include <ngx_core.h>
9 #include <ngx_http.h>
10
11
12 typedef struct {
13 size_t sbrk_size;
14 } ngx_http_degradation_main_conf_t;
15
16
17 typedef struct {
18 ngx_uint_t degrade;
19 } ngx_http_degradation_loc_conf_t;
20
21
22 static ngx_conf_enum_t ngx_http_degrade[] = {
23 { ngx_string("204"), 204 },
24 { ngx_string("444"), 444 },
25 { ngx_null_string, 0 }
26 };
27
28
29 static void *ngx_http_degradation_create_main_conf(ngx_conf_t *cf);
30 static void *ngx_http_degradation_create_loc_conf(ngx_conf_t *cf);
31 static char *ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent,
32 void *child);
33 static char *ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd,
34 void *conf);
35 static ngx_int_t ngx_http_degradation_init(ngx_conf_t *cf);
36
37
38 static ngx_command_t ngx_http_degradation_commands[] = {
39
40 { ngx_string("degradation"),
41 NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
42 ngx_http_degradation,
43 NGX_HTTP_MAIN_CONF_OFFSET,
44 0,
45 NULL },
46
47 { ngx_string("degrade"),
48 NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
49 ngx_conf_set_enum_slot,
50 NGX_HTTP_LOC_CONF_OFFSET,
51 offsetof(ngx_http_degradation_loc_conf_t, degrade),
52 &ngx_http_degrade },
53
54 ngx_null_command
55 };
56
57
58 static ngx_http_module_t ngx_http_degradation_module_ctx = {
59 NULL, /* preconfiguration */
60 ngx_http_degradation_init, /* postconfiguration */
61
62 ngx_http_degradation_create_main_conf, /* create main configuration */
63 NULL, /* init main configuration */
64
65 NULL, /* create server configuration */
66 NULL, /* merge server configuration */
67
68 ngx_http_degradation_create_loc_conf, /* create location configuration */
69 ngx_http_degradation_merge_loc_conf /* merge location configuration */
70 };
71
72
73 ngx_module_t ngx_http_degradation_module = {
74 NGX_MODULE_V1,
75 &ngx_http_degradation_module_ctx, /* module context */
76 ngx_http_degradation_commands, /* module directives */
77 NGX_HTTP_MODULE, /* module type */
78 NULL, /* init master */
79 NULL, /* init module */
80 NULL, /* init process */
81 NULL, /* init thread */
82 NULL, /* exit thread */
83 NULL, /* exit process */
84 NULL, /* exit master */
85 NGX_MODULE_V1_PADDING
86 };
87
88
89 static ngx_int_t
90 ngx_http_degradation_handler(ngx_http_request_t *r)
91 {
92 ngx_http_degradation_loc_conf_t *dlcf;
93
94 dlcf = ngx_http_get_module_loc_conf(r, ngx_http_degradation_module);
95
96 if (dlcf->degrade && ngx_http_degraded(r)) {
97 return dlcf->degrade;
98 }
99
100 return NGX_DECLINED;
101 }
102
103
104 ngx_uint_t
105 ngx_http_degraded(ngx_http_request_t *r)
106 {
107 time_t now;
108 ngx_uint_t log;
109 static size_t sbrk_size;
110 static time_t sbrk_time;
111 ngx_http_degradation_main_conf_t *dmcf;
112
113 dmcf = ngx_http_get_module_main_conf(r, ngx_http_degradation_module);
114
115 if (dmcf->sbrk_size) {
116
117 log = 0;
118 now = ngx_time();
119
120 /* lock mutex */
121
122 if (now != sbrk_time) {
123
124 /*
125 * ELF/i386 is loaded at 0x08000000, 128M
126 * ELF/amd64 is loaded at 0x00400000, 4M
127 *
128 * use a function address to substract the loading address
129 */
130
131 sbrk_size = (size_t) sbrk(0) - ((uintptr_t) ngx_palloc & ~0x3FFFFF);
132 sbrk_time = now;
133 log = 1;
134 }
135
136 /* unlock mutex */
137
138 if (sbrk_size >= dmcf->sbrk_size) {
139 if (log) {
140 ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
141 "degradation sbrk:%uzM",
142 sbrk_size / (1024 * 1024));
143 }
144
145 return 1;
146 }
147 }
148
149 return 0;
150 }
151
152
153 static void *
154 ngx_http_degradation_create_main_conf(ngx_conf_t *cf)
155 {
156 ngx_http_degradation_main_conf_t *dmcf;
157
158 dmcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_degradation_main_conf_t));
159 if (dmcf == NULL) {
160 return NULL;
161 }
162
163 return dmcf;
164 }
165
166
167 static void *
168 ngx_http_degradation_create_loc_conf(ngx_conf_t *cf)
169 {
170 ngx_http_degradation_loc_conf_t *conf;
171
172 conf = ngx_palloc(cf->pool, sizeof(ngx_http_degradation_loc_conf_t));
173 if (conf == NULL) {
174 return NULL;
175 }
176
177 conf->degrade = NGX_CONF_UNSET_UINT;
178
179 return conf;
180 }
181
182
183 static char *
184 ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
185 {
186 ngx_http_degradation_loc_conf_t *prev = parent;
187 ngx_http_degradation_loc_conf_t *conf = child;
188
189 ngx_conf_merge_uint_value(conf->degrade, prev->degrade, 0);
190
191 return NGX_CONF_OK;
192 }
193
194
195 static char *
196 ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
197 {
198 ngx_http_degradation_main_conf_t *dmcf = conf;
199
200 ngx_str_t *value, s;
201
202 value = cf->args->elts;
203
204 if (ngx_strncmp(value[1].data, "sbrk=", 5) == 0) {
205
206 s.len = value[1].len - 5;
207 s.data = value[1].data + 5;
208
209 dmcf->sbrk_size = ngx_parse_size(&s);
210 if (dmcf->sbrk_size == (size_t) NGX_ERROR) {
211 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
212 "invalid sbrk size \"%V\"", &value[1]);
213 return NGX_CONF_ERROR;
214 }
215
216 return NGX_CONF_OK;
217 }
218
219 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
220 "invalid parameter \"%V\"", &value[1]);
221
222 return NGX_CONF_ERROR;
223 }
224
225
226 static ngx_int_t
227 ngx_http_degradation_init(ngx_conf_t *cf)
228 {
229 ngx_http_handler_pt *h;
230 ngx_http_core_main_conf_t *cmcf;
231
232 cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
233
234 h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers);
235 if (h == NULL) {
236 return NGX_ERROR;
237 }
238
239 *h = ngx_http_degradation_handler;
240
241 return NGX_OK;
242 }