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1.1 misho 1:
2: /*
3: * Copyright (C) Igor Sysoev
4: * Copyright (C) Nginx, Inc.
5: */
6:
7:
8: #include <ngx_config.h>
9: #include <ngx_core.h>
10: #include <ngx_http.h>
11:
12:
13: typedef struct {
14: size_t sbrk_size;
15: } ngx_http_degradation_main_conf_t;
16:
17:
18: typedef struct {
19: ngx_uint_t degrade;
20: } ngx_http_degradation_loc_conf_t;
21:
22:
23: static ngx_conf_enum_t ngx_http_degrade[] = {
24: { ngx_string("204"), 204 },
25: { ngx_string("444"), 444 },
26: { ngx_null_string, 0 }
27: };
28:
29:
30: static void *ngx_http_degradation_create_main_conf(ngx_conf_t *cf);
31: static void *ngx_http_degradation_create_loc_conf(ngx_conf_t *cf);
32: static char *ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent,
33: void *child);
34: static char *ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd,
35: void *conf);
36: static ngx_int_t ngx_http_degradation_init(ngx_conf_t *cf);
37:
38:
39: static ngx_command_t ngx_http_degradation_commands[] = {
40:
41: { ngx_string("degradation"),
42: NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
43: ngx_http_degradation,
44: NGX_HTTP_MAIN_CONF_OFFSET,
45: 0,
46: NULL },
47:
48: { ngx_string("degrade"),
49: NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
50: ngx_conf_set_enum_slot,
51: NGX_HTTP_LOC_CONF_OFFSET,
52: offsetof(ngx_http_degradation_loc_conf_t, degrade),
53: &ngx_http_degrade },
54:
55: ngx_null_command
56: };
57:
58:
59: static ngx_http_module_t ngx_http_degradation_module_ctx = {
60: NULL, /* preconfiguration */
61: ngx_http_degradation_init, /* postconfiguration */
62:
63: ngx_http_degradation_create_main_conf, /* create main configuration */
64: NULL, /* init main configuration */
65:
66: NULL, /* create server configuration */
67: NULL, /* merge server configuration */
68:
69: ngx_http_degradation_create_loc_conf, /* create location configuration */
70: ngx_http_degradation_merge_loc_conf /* merge location configuration */
71: };
72:
73:
74: ngx_module_t ngx_http_degradation_module = {
75: NGX_MODULE_V1,
76: &ngx_http_degradation_module_ctx, /* module context */
77: ngx_http_degradation_commands, /* module directives */
78: NGX_HTTP_MODULE, /* module type */
79: NULL, /* init master */
80: NULL, /* init module */
81: NULL, /* init process */
82: NULL, /* init thread */
83: NULL, /* exit thread */
84: NULL, /* exit process */
85: NULL, /* exit master */
86: NGX_MODULE_V1_PADDING
87: };
88:
89:
90: static ngx_int_t
91: ngx_http_degradation_handler(ngx_http_request_t *r)
92: {
93: ngx_http_degradation_loc_conf_t *dlcf;
94:
95: dlcf = ngx_http_get_module_loc_conf(r, ngx_http_degradation_module);
96:
97: if (dlcf->degrade && ngx_http_degraded(r)) {
98: return dlcf->degrade;
99: }
100:
101: return NGX_DECLINED;
102: }
103:
104:
105: ngx_uint_t
106: ngx_http_degraded(ngx_http_request_t *r)
107: {
108: time_t now;
109: ngx_uint_t log;
110: static size_t sbrk_size;
111: static time_t sbrk_time;
112: ngx_http_degradation_main_conf_t *dmcf;
113:
114: dmcf = ngx_http_get_module_main_conf(r, ngx_http_degradation_module);
115:
116: if (dmcf->sbrk_size) {
117:
118: log = 0;
119: now = ngx_time();
120:
121: /* lock mutex */
122:
123: if (now != sbrk_time) {
124:
125: /*
126: * ELF/i386 is loaded at 0x08000000, 128M
127: * ELF/amd64 is loaded at 0x00400000, 4M
128: *
129: * use a function address to subtract the loading address
130: */
131:
132: sbrk_size = (size_t) sbrk(0) - ((uintptr_t) ngx_palloc & ~0x3FFFFF);
133: sbrk_time = now;
134: log = 1;
135: }
136:
137: /* unlock mutex */
138:
139: if (sbrk_size >= dmcf->sbrk_size) {
140: if (log) {
141: ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
142: "degradation sbrk:%uzM",
143: sbrk_size / (1024 * 1024));
144: }
145:
146: return 1;
147: }
148: }
149:
150: return 0;
151: }
152:
153:
154: static void *
155: ngx_http_degradation_create_main_conf(ngx_conf_t *cf)
156: {
157: ngx_http_degradation_main_conf_t *dmcf;
158:
159: dmcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_degradation_main_conf_t));
160: if (dmcf == NULL) {
161: return NULL;
162: }
163:
164: return dmcf;
165: }
166:
167:
168: static void *
169: ngx_http_degradation_create_loc_conf(ngx_conf_t *cf)
170: {
171: ngx_http_degradation_loc_conf_t *conf;
172:
173: conf = ngx_palloc(cf->pool, sizeof(ngx_http_degradation_loc_conf_t));
174: if (conf == NULL) {
175: return NULL;
176: }
177:
178: conf->degrade = NGX_CONF_UNSET_UINT;
179:
180: return conf;
181: }
182:
183:
184: static char *
185: ngx_http_degradation_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
186: {
187: ngx_http_degradation_loc_conf_t *prev = parent;
188: ngx_http_degradation_loc_conf_t *conf = child;
189:
190: ngx_conf_merge_uint_value(conf->degrade, prev->degrade, 0);
191:
192: return NGX_CONF_OK;
193: }
194:
195:
196: static char *
197: ngx_http_degradation(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
198: {
199: ngx_http_degradation_main_conf_t *dmcf = conf;
200:
201: ngx_str_t *value, s;
202:
203: value = cf->args->elts;
204:
205: if (ngx_strncmp(value[1].data, "sbrk=", 5) == 0) {
206:
207: s.len = value[1].len - 5;
208: s.data = value[1].data + 5;
209:
210: dmcf->sbrk_size = ngx_parse_size(&s);
211: if (dmcf->sbrk_size == (size_t) NGX_ERROR) {
212: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
213: "invalid sbrk size \"%V\"", &value[1]);
214: return NGX_CONF_ERROR;
215: }
216:
217: return NGX_CONF_OK;
218: }
219:
220: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
221: "invalid parameter \"%V\"", &value[1]);
222:
223: return NGX_CONF_ERROR;
224: }
225:
226:
227: static ngx_int_t
228: ngx_http_degradation_init(ngx_conf_t *cf)
229: {
230: ngx_http_handler_pt *h;
231: ngx_http_core_main_conf_t *cmcf;
232:
233: cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
234:
235: h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers);
236: if (h == NULL) {
237: return NGX_ERROR;
238: }
239:
240: *h = ngx_http_degradation_handler;
241:
242: return NGX_OK;
243: }