Mercurial > hg > nginx
view src/http/modules/ngx_http_access_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 | bab3488bd113 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { in_addr_t mask; in_addr_t addr; ngx_uint_t deny; /* unsigned deny:1; */ } ngx_http_access_rule_t; #if (NGX_HAVE_INET6) typedef struct { struct in6_addr addr; struct in6_addr mask; ngx_uint_t deny; /* unsigned deny:1; */ } ngx_http_access_rule6_t; #endif typedef struct { ngx_array_t *rules; /* array of ngx_http_access_rule_t */ #if (NGX_HAVE_INET6) ngx_array_t *rules6; /* array of ngx_http_access_rule6_t */ #endif } ngx_http_access_loc_conf_t; static ngx_int_t ngx_http_access_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_access_inet(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, in_addr_t addr); #if (NGX_HAVE_INET6) static ngx_int_t ngx_http_access_inet6(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, u_char *p); #endif static ngx_int_t ngx_http_access_found(ngx_http_request_t *r, ngx_uint_t deny); static char *ngx_http_access_rule(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_http_access_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_access_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_access_init(ngx_conf_t *cf); static ngx_command_t ngx_http_access_commands[] = { { ngx_string("allow"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF |NGX_CONF_TAKE1, ngx_http_access_rule, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("deny"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF |NGX_CONF_TAKE1, ngx_http_access_rule, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_access_module_ctx = { NULL, /* preconfiguration */ ngx_http_access_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_access_create_loc_conf, /* create location configuration */ ngx_http_access_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_access_module = { NGX_MODULE_V1, &ngx_http_access_module_ctx, /* module context */ ngx_http_access_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_int_t ngx_http_access_handler(ngx_http_request_t *r) { struct sockaddr_in *sin; ngx_http_access_loc_conf_t *alcf; #if (NGX_HAVE_INET6) u_char *p; in_addr_t addr; struct sockaddr_in6 *sin6; #endif alcf = ngx_http_get_module_loc_conf(r, ngx_http_access_module); switch (r->connection->sockaddr->sa_family) { case AF_INET: if (alcf->rules) { sin = (struct sockaddr_in *) r->connection->sockaddr; return ngx_http_access_inet(r, alcf, sin->sin_addr.s_addr); } break; #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) r->connection->sockaddr; p = sin6->sin6_addr.s6_addr; if (alcf->rules && IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) { addr = p[12] << 24; addr += p[13] << 16; addr += p[14] << 8; addr += p[15]; return ngx_http_access_inet(r, alcf, htonl(addr)); } if (alcf->rules6) { return ngx_http_access_inet6(r, alcf, p); } #endif } return NGX_DECLINED; } static ngx_int_t ngx_http_access_inet(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, in_addr_t addr) { ngx_uint_t i; ngx_http_access_rule_t *rule; rule = alcf->rules->elts; for (i = 0; i < alcf->rules->nelts; i++) { ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "access: %08XD %08XD %08XD", addr, rule[i].mask, rule[i].addr); if ((addr & rule[i].mask) == rule[i].addr) { return ngx_http_access_found(r, rule[i].deny); } } return NGX_DECLINED; } #if (NGX_HAVE_INET6) static ngx_int_t ngx_http_access_inet6(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, u_char *p) { ngx_uint_t n; ngx_uint_t i; ngx_http_access_rule6_t *rule6; rule6 = alcf->rules6->elts; for (i = 0; i < alcf->rules6->nelts; i++) { #if (NGX_DEBUG) { size_t cl, ml, al; u_char ct[NGX_INET6_ADDRSTRLEN]; u_char mt[NGX_INET6_ADDRSTRLEN]; u_char at[NGX_INET6_ADDRSTRLEN]; cl = ngx_inet6_ntop(p, ct, NGX_INET6_ADDRSTRLEN); ml = ngx_inet6_ntop(rule6[i].mask.s6_addr, mt, NGX_INET6_ADDRSTRLEN); al = ngx_inet6_ntop(rule6[i].addr.s6_addr, at, NGX_INET6_ADDRSTRLEN); ngx_log_debug6(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "access: %*s %*s %*s", cl, ct, ml, mt, al, at); } #endif for (n = 0; n < 16; n++) { if ((p[n] & rule6[i].mask.s6_addr[n]) != rule6[i].addr.s6_addr[n]) { goto next; } } return ngx_http_access_found(r, rule6[i].deny); next: continue; } return NGX_DECLINED; } #endif static ngx_int_t ngx_http_access_found(ngx_http_request_t *r, ngx_uint_t deny) { ngx_http_core_loc_conf_t *clcf; if (deny) { clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (clcf->satisfy == NGX_HTTP_SATISFY_ALL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "access forbidden by rule"); } return NGX_HTTP_FORBIDDEN; } return NGX_OK; } static char * ngx_http_access_rule(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_access_loc_conf_t *alcf = conf; ngx_int_t rc; ngx_uint_t all; ngx_str_t *value; ngx_cidr_t cidr; ngx_http_access_rule_t *rule; #if (NGX_HAVE_INET6) ngx_http_access_rule6_t *rule6; #endif ngx_memzero(&cidr, sizeof(ngx_cidr_t)); value = cf->args->elts; all = (value[1].len == 3 && ngx_strcmp(value[1].data, "all") == 0); if (!all) { rc = ngx_ptocidr(&value[1], &cidr); if (rc == NGX_ERROR) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[1]); return NGX_CONF_ERROR; } if (rc == NGX_DONE) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "low address bits of %V are meaningless", &value[1]); } } switch (cidr.family) { #if (NGX_HAVE_INET6) case AF_INET6: case 0: /* all */ if (alcf->rules6 == NULL) { alcf->rules6 = ngx_array_create(cf->pool, 4, sizeof(ngx_http_access_rule6_t)); if (alcf->rules6 == NULL) { return NGX_CONF_ERROR; } } rule6 = ngx_array_push(alcf->rules6); if (rule6 == NULL) { return NGX_CONF_ERROR; } rule6->mask = cidr.u.in6.mask; rule6->addr = cidr.u.in6.addr; rule6->deny = (value[0].data[0] == 'd') ? 1 : 0; if (!all) { break; } /* "all" passes through */ #endif default: /* AF_INET */ if (alcf->rules == NULL) { alcf->rules = ngx_array_create(cf->pool, 4, sizeof(ngx_http_access_rule_t)); if (alcf->rules == NULL) { return NGX_CONF_ERROR; } } rule = ngx_array_push(alcf->rules); if (rule == NULL) { return NGX_CONF_ERROR; } rule->mask = cidr.u.in.mask; rule->addr = cidr.u.in.addr; rule->deny = (value[0].data[0] == 'd') ? 1 : 0; } return NGX_CONF_OK; } static void * ngx_http_access_create_loc_conf(ngx_conf_t *cf) { ngx_http_access_loc_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_access_loc_conf_t)); if (conf == NULL) { return NULL; } return conf; } static char * ngx_http_access_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_access_loc_conf_t *prev = parent; ngx_http_access_loc_conf_t *conf = child; if (conf->rules == NULL) { conf->rules = prev->rules; } #if (NGX_HAVE_INET6) if (conf->rules6 == NULL) { conf->rules6 = prev->rules6; } #endif return NGX_CONF_OK; } static ngx_int_t ngx_http_access_init(ngx_conf_t *cf) { ngx_http_handler_pt *h; ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); h = ngx_array_push(&cmcf->phases[NGX_HTTP_ACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_access_handler; return NGX_OK; }