Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_browser_module.c @ 4207:4fc91bae6f83
Better recheck of dead upstream servers.
Previously nginx used to mark backend again as live as soon as fail_timeout
passes (10s by default) since last failure. On the other hand, detecting
dead backend takes up to 60s (proxy_connect_timeout) in typical situation
"backend is down and doesn't respond to any packets". This resulted in
suboptimal behaviour in the above situation (up to 23% of requests were
directed to dead backend with default settings).
More detailed description of the problem may be found here (in Russian):
http://mailman.nginx.org/pipermail/nginx-ru/2011-August/042172.html
Fix is to only allow one request after fail_timeout passes, and
mark backend as "live" only if this request succeeds.
Note that with new code backend will not be marked "live" unless "check"
request is completed, and this may take a while in some specific workloads
(e.g. streaming). This is believed to be acceptable.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 12 Oct 2011 14:22:48 +0000 |
parents | c7d57b539248 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> /* * The module can check browser versions conforming to the following formats: * X, X.X, X.X.X, and X.X.X.X. The maximum values of each format may be * 4000, 4000.99, 4000.99.99, and 4000.99.99.99. */ #define NGX_HTTP_MODERN_BROWSER 0 #define NGX_HTTP_ANCIENT_BROWSER 1 typedef struct { u_char browser[12]; size_t skip; size_t add; u_char name[12]; } ngx_http_modern_browser_mask_t; typedef struct { ngx_uint_t version; size_t skip; size_t add; u_char name[12]; } ngx_http_modern_browser_t; typedef struct { ngx_str_t name; ngx_http_get_variable_pt handler; uintptr_t data; } ngx_http_browser_variable_t; typedef struct { ngx_array_t *modern_browsers; ngx_array_t *ancient_browsers; ngx_http_variable_value_t *modern_browser_value; ngx_http_variable_value_t *ancient_browser_value; unsigned modern_unlisted_browsers:1; unsigned netscape4:1; } ngx_http_browser_conf_t; static ngx_int_t ngx_http_msie_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_http_browser_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static ngx_uint_t ngx_http_browser(ngx_http_request_t *r, ngx_http_browser_conf_t *cf); static ngx_int_t ngx_http_browser_add_variable(ngx_conf_t *cf); static void *ngx_http_browser_create_conf(ngx_conf_t *cf); static char *ngx_http_browser_merge_conf(ngx_conf_t *cf, void *parent, void *child); static int ngx_libc_cdecl ngx_http_modern_browser_sort(const void *one, const void *two); static char *ngx_http_modern_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_ancient_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_modern_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_ancient_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_browser_commands[] = { { ngx_string("modern_browser"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE12, ngx_http_modern_browser, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("ancient_browser"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE, ngx_http_ancient_browser, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("modern_browser_value"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_modern_browser_value, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("ancient_browser_value"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_ancient_browser_value, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_browser_module_ctx = { ngx_http_browser_add_variable, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_browser_create_conf, /* create location configuration */ ngx_http_browser_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_browser_module = { NGX_MODULE_V1, &ngx_http_browser_module_ctx, /* module context */ ngx_http_browser_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_http_modern_browser_mask_t ngx_http_modern_browser_masks[] = { /* Opera must be the first browser to check */ /* * "Opera/7.50 (X11; FreeBSD i386; U) [en]" * "Mozilla/5.0 (X11; FreeBSD i386; U) Opera 7.50 [en]" * "Mozilla/4.0 (compatible; MSIE 6.0; X11; FreeBSD i386) Opera 7.50 [en]" * "Opera/8.0 (Windows NT 5.1; U; ru)" * "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; en) Opera 8.0" * "Opera/9.01 (X11; FreeBSD 6 i386; U; en)" */ { "opera", 0, sizeof("Opera ") - 1, "Opera"}, /* "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)" */ { "msie", sizeof("Mozilla/4.0 (compatible; ") - 1, sizeof("MSIE ") - 1, "MSIE "}, /* * "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020610" * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.5) Gecko/20031006" * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.6) Gecko/20040206 * Firefox/0.8" * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.7.8) * Gecko/20050511 Firefox/1.0.4" * "Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.0.5) Gecko/20060729 * Firefox/1.5.0.5" */ { "gecko", sizeof("Mozilla/5.0 (") - 1, sizeof("rv:") - 1, "rv:"}, /* * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ru-ru) AppleWebKit/125.2 * (KHTML, like Gecko) Safari/125.7" * "Mozilla/5.0 (SymbianOS/9.1; U; en-us) AppleWebKit/413 * (KHTML, like Gecko) Safari/413" * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en) AppleWebKit/418 * (KHTML, like Gecko) Safari/417.9.3" * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ru-ru) AppleWebKit/418.8 * (KHTML, like Gecko) Safari/419.3" */ { "safari", sizeof("Mozilla/5.0 (") - 1, sizeof("Safari/") - 1, "Safari/"}, /* * "Mozilla/5.0 (compatible; Konqueror/3.1; Linux)" * "Mozilla/5.0 (compatible; Konqueror/3.4; Linux) KHTML/3.4.2 (like Gecko)" * "Mozilla/5.0 (compatible; Konqueror/3.5; FreeBSD) KHTML/3.5.1 * (like Gecko)" */ { "konqueror", sizeof("Mozilla/5.0 (compatible; ") - 1, sizeof("Konqueror/") - 1, "Konqueror/"}, { "", 0, 0, "" } }; static ngx_http_browser_variable_t ngx_http_browsers[] = { { ngx_string("msie"), ngx_http_msie_variable, 0 }, { ngx_string("modern_browser"), ngx_http_browser_variable, NGX_HTTP_MODERN_BROWSER }, { ngx_string("ancient_browser"), ngx_http_browser_variable, NGX_HTTP_ANCIENT_BROWSER }, { ngx_null_string, NULL, 0 } }; static ngx_int_t ngx_http_browser_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_uint_t rc; ngx_http_browser_conf_t *cf; cf = ngx_http_get_module_loc_conf(r, ngx_http_browser_module); rc = ngx_http_browser(r, cf); if (data == NGX_HTTP_MODERN_BROWSER && rc == NGX_HTTP_MODERN_BROWSER) { *v = *cf->modern_browser_value; return NGX_OK; } if (data == NGX_HTTP_ANCIENT_BROWSER && rc == NGX_HTTP_ANCIENT_BROWSER) { *v = *cf->ancient_browser_value; return NGX_OK; } *v = ngx_http_variable_null_value; return NGX_OK; } static ngx_uint_t ngx_http_browser(ngx_http_request_t *r, ngx_http_browser_conf_t *cf) { size_t len; u_char *name, *ua, *last, c; ngx_str_t *ancient; ngx_uint_t i, version, ver, scale; ngx_http_modern_browser_t *modern; if (r->headers_in.user_agent == NULL) { if (cf->modern_unlisted_browsers) { return NGX_HTTP_MODERN_BROWSER; } return NGX_HTTP_ANCIENT_BROWSER; } ua = r->headers_in.user_agent->value.data; len = r->headers_in.user_agent->value.len; last = ua + len; if (cf->modern_browsers) { modern = cf->modern_browsers->elts; for (i = 0; i < cf->modern_browsers->nelts; i++) { name = ua + modern[i].skip; if (name >= last) { continue; } name = (u_char *) ngx_strstr(name, modern[i].name); if (name == NULL) { continue; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "browser: \"%s\"", name); name += modern[i].add; if (name >= last) { continue; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "version: \"%ui\" \"%s\"", modern[i].version, name); version = 0; ver = 0; scale = 1000000; while (name < last) { c = *name++; if (c >= '0' && c <= '9') { ver = ver * 10 + (c - '0'); continue; } if (c == '.') { version += ver * scale; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "version: \"%ui\" \"%ui\"", modern[i].version, version); if (version > modern[i].version) { return NGX_HTTP_MODERN_BROWSER; } ver = 0; scale /= 100; continue; } break; } version += ver * scale; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "version: \"%ui\" \"%ui\"", modern[i].version, version); if (version >= modern[i].version) { return NGX_HTTP_MODERN_BROWSER; } return NGX_HTTP_ANCIENT_BROWSER; } if (!cf->modern_unlisted_browsers) { return NGX_HTTP_ANCIENT_BROWSER; } } if (cf->netscape4) { if (len > sizeof("Mozilla/4.72 ") - 1 && ngx_strncmp(ua, "Mozilla/", sizeof("Mozilla/") - 1) == 0 && ua[8] > '0' && ua[8] < '5') { return NGX_HTTP_ANCIENT_BROWSER; } } if (cf->ancient_browsers) { ancient = cf->ancient_browsers->elts; for (i = 0; i < cf->ancient_browsers->nelts; i++) { if (len >= ancient[i].len && ngx_strstr(ua, ancient[i].data) != NULL) { return NGX_HTTP_ANCIENT_BROWSER; } } } if (cf->modern_unlisted_browsers) { return NGX_HTTP_MODERN_BROWSER; } return NGX_HTTP_ANCIENT_BROWSER; } static ngx_int_t ngx_http_msie_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { if (r->headers_in.msie) { *v = ngx_http_variable_true_value; return NGX_OK; } *v = ngx_http_variable_null_value; return NGX_OK; } static ngx_int_t ngx_http_browser_add_variable(ngx_conf_t *cf) { ngx_http_browser_variable_t *var; ngx_http_variable_t *v; for (var = ngx_http_browsers; var->name.len; var++) { v = ngx_http_add_variable(cf, &var->name, NGX_HTTP_VAR_CHANGEABLE); if (v == NULL) { return NGX_ERROR; } v->get_handler = var->handler; v->data = var->data; } return NGX_OK; } static void * ngx_http_browser_create_conf(ngx_conf_t *cf) { ngx_http_browser_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_browser_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->modern_browsers = NULL; * conf->ancient_browsers = NULL; * conf->modern_browser_value = NULL; * conf->ancient_browser_value = NULL; * * conf->modern_unlisted_browsers = 0; * conf->netscape4 = 0; */ return conf; } static char * ngx_http_browser_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_browser_conf_t *prev = parent; ngx_http_browser_conf_t *conf = child; ngx_uint_t i, n; ngx_http_modern_browser_t *browsers, *opera; /* * At the merge the skip field is used to store the browser slot, * it will be used in sorting and then will overwritten * with a real skip value. The zero value means Opera. */ if (conf->modern_browsers == NULL) { conf->modern_browsers = prev->modern_browsers; } else { browsers = conf->modern_browsers->elts; for (i = 0; i < conf->modern_browsers->nelts; i++) { if (browsers[i].skip == 0) { goto found; } } /* * Opera may contain MSIE string, so if Opera was not enumerated * as modern browsers, then add it and set a unreachable version */ opera = ngx_array_push(conf->modern_browsers); if (opera == NULL) { return NGX_CONF_ERROR; } opera->skip = 0; opera->version = 4001000000U; browsers = conf->modern_browsers->elts; found: ngx_qsort(browsers, (size_t) conf->modern_browsers->nelts, sizeof(ngx_http_modern_browser_t), ngx_http_modern_browser_sort); for (i = 0; i < conf->modern_browsers->nelts; i++) { n = browsers[i].skip; browsers[i].skip = ngx_http_modern_browser_masks[n].skip; browsers[i].add = ngx_http_modern_browser_masks[n].add; (void) ngx_cpystrn(browsers[i].name, ngx_http_modern_browser_masks[n].name, 12); } } if (conf->ancient_browsers == NULL) { conf->ancient_browsers = prev->ancient_browsers; } if (conf->modern_browser_value == NULL) { conf->modern_browser_value = prev->modern_browser_value; } if (conf->modern_browser_value == NULL) { conf->modern_browser_value = &ngx_http_variable_true_value; } if (conf->ancient_browser_value == NULL) { conf->ancient_browser_value = prev->ancient_browser_value; } if (conf->ancient_browser_value == NULL) { conf->ancient_browser_value = &ngx_http_variable_true_value; } return NGX_CONF_OK; } static int ngx_libc_cdecl ngx_http_modern_browser_sort(const void *one, const void *two) { ngx_http_modern_browser_t *first = (ngx_http_modern_browser_t *) one; ngx_http_modern_browser_t *second = (ngx_http_modern_browser_t *) two; return (first->skip - second->skip); } static char * ngx_http_modern_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; u_char c; ngx_str_t *value; ngx_uint_t i, n, version, ver, scale; ngx_http_modern_browser_t *browser; ngx_http_modern_browser_mask_t *mask; value = cf->args->elts; if (cf->args->nelts == 2) { if (ngx_strcmp(value[1].data, "unlisted") == 0) { bcf->modern_unlisted_browsers = 1; return NGX_CONF_OK; } return NGX_CONF_ERROR; } if (bcf->modern_browsers == NULL) { bcf->modern_browsers = ngx_array_create(cf->pool, 5, sizeof(ngx_http_modern_browser_t)); if (bcf->modern_browsers == NULL) { return NGX_CONF_ERROR; } } browser = ngx_array_push(bcf->modern_browsers); if (browser == NULL) { return NGX_CONF_ERROR; } mask = ngx_http_modern_browser_masks; for (n = 0; mask[n].browser[0] != '\0'; n++) { if (ngx_strcasecmp(mask[n].browser, value[1].data) == 0) { goto found; } } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown browser name \"%V\"", &value[1]); return NGX_CONF_ERROR; found: /* * at this stage the skip field is used to store the browser slot, * it will be used in sorting in merge stage and then will overwritten * with a real value */ browser->skip = n; version = 0; ver = 0; scale = 1000000; for (i = 0; i < value[2].len; i++) { c = value[2].data[i]; if (c >= '0' && c <= '9') { ver = ver * 10 + (c - '0'); continue; } if (c == '.') { version += ver * scale; ver = 0; scale /= 100; continue; } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid browser version \"%V\"", &value[2]); return NGX_CONF_ERROR; } version += ver * scale; browser->version = version; return NGX_CONF_OK; } static char * ngx_http_ancient_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; ngx_str_t *value, *browser; ngx_uint_t i; value = cf->args->elts; for (i = 1; i < cf->args->nelts; i++) { if (ngx_strcmp(value[i].data, "netscape4") == 0) { bcf->netscape4 = 1; continue; } if (bcf->ancient_browsers == NULL) { bcf->ancient_browsers = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t)); if (bcf->ancient_browsers == NULL) { return NGX_CONF_ERROR; } } browser = ngx_array_push(bcf->ancient_browsers); if (browser == NULL) { return NGX_CONF_ERROR; } *browser = value[i]; } return NGX_CONF_OK; } static char * ngx_http_modern_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; ngx_str_t *value; bcf->modern_browser_value = ngx_palloc(cf->pool, sizeof(ngx_http_variable_value_t)); if (bcf->modern_browser_value == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; bcf->modern_browser_value->len = value[1].len; bcf->modern_browser_value->valid = 1; bcf->modern_browser_value->no_cacheable = 0; bcf->modern_browser_value->not_found = 0; bcf->modern_browser_value->data = value[1].data; return NGX_CONF_OK; } static char * ngx_http_ancient_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; ngx_str_t *value; bcf->ancient_browser_value = ngx_palloc(cf->pool, sizeof(ngx_http_variable_value_t)); if (bcf->ancient_browser_value == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; bcf->ancient_browser_value->len = value[1].len; bcf->ancient_browser_value->valid = 1; bcf->ancient_browser_value->no_cacheable = 0; bcf->ancient_browser_value->not_found = 0; bcf->ancient_browser_value->data = value[1].data; return NGX_CONF_OK; }