Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_map_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 | ace14fd91086 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_uint_t hash_max_size; ngx_uint_t hash_bucket_size; } ngx_http_map_conf_t; typedef struct { ngx_hash_keys_arrays_t keys; ngx_array_t *values_hash; ngx_array_t var_values; #if (NGX_PCRE) ngx_array_t regexes; #endif ngx_http_variable_value_t *default_value; ngx_conf_t *cf; ngx_uint_t hostnames; /* unsigned hostnames:1 */ } ngx_http_map_conf_ctx_t; typedef struct { ngx_http_map_t map; ngx_http_complex_value_t value; ngx_http_variable_value_t *default_value; ngx_uint_t hostnames; /* unsigned hostnames:1 */ } ngx_http_map_ctx_t; static int ngx_libc_cdecl ngx_http_map_cmp_dns_wildcards(const void *one, const void *two); static void *ngx_http_map_create_conf(ngx_conf_t *cf); static char *ngx_http_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf); static ngx_command_t ngx_http_map_commands[] = { { ngx_string("map"), NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2, ngx_http_map_block, NGX_HTTP_MAIN_CONF_OFFSET, 0, NULL }, { ngx_string("map_hash_max_size"), NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_HTTP_MAIN_CONF_OFFSET, offsetof(ngx_http_map_conf_t, hash_max_size), NULL }, { ngx_string("map_hash_bucket_size"), NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_HTTP_MAIN_CONF_OFFSET, offsetof(ngx_http_map_conf_t, hash_bucket_size), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_map_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ ngx_http_map_create_conf, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_map_module = { NGX_MODULE_V1, &ngx_http_map_module_ctx, /* module context */ ngx_http_map_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_map_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_http_map_ctx_t *map = (ngx_http_map_ctx_t *) data; size_t len; ngx_str_t val; ngx_http_variable_value_t *value; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http map started"); if (ngx_http_complex_value(r, &map->value, &val) != NGX_OK) { return NGX_ERROR; } len = val.len; if (len && map->hostnames && val.data[len - 1] == '.') { len--; } value = ngx_http_map_find(r, &map->map, &val); if (value == NULL) { value = map->default_value; } if (!value->valid) { value = ngx_http_get_flushed_variable(r, (ngx_uint_t) value->data); if (value == NULL || value->not_found) { value = &ngx_http_variable_null_value; } } *v = *value; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http map: \"%v\" \"%v\"", &val, v); return NGX_OK; } static void * ngx_http_map_create_conf(ngx_conf_t *cf) { ngx_http_map_conf_t *mcf; mcf = ngx_palloc(cf->pool, sizeof(ngx_http_map_conf_t)); if (mcf == NULL) { return NULL; } mcf->hash_max_size = NGX_CONF_UNSET_UINT; mcf->hash_bucket_size = NGX_CONF_UNSET_UINT; return mcf; } static char * ngx_http_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_map_conf_t *mcf = conf; char *rv; ngx_str_t *value, name; ngx_conf_t save; ngx_pool_t *pool; ngx_hash_init_t hash; ngx_http_map_ctx_t *map; ngx_http_variable_t *var; ngx_http_map_conf_ctx_t ctx; ngx_http_compile_complex_value_t ccv; if (mcf->hash_max_size == NGX_CONF_UNSET_UINT) { mcf->hash_max_size = 2048; } if (mcf->hash_bucket_size == NGX_CONF_UNSET_UINT) { mcf->hash_bucket_size = ngx_cacheline_size; } else { mcf->hash_bucket_size = ngx_align(mcf->hash_bucket_size, ngx_cacheline_size); } map = ngx_pcalloc(cf->pool, sizeof(ngx_http_map_ctx_t)); if (map == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &map->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } name = value[2]; name.len--; name.data++; var = ngx_http_add_variable(cf, &name, NGX_HTTP_VAR_CHANGEABLE); if (var == NULL) { return NGX_CONF_ERROR; } var->get_handler = ngx_http_map_variable; var->data = (uintptr_t) map; pool = ngx_create_pool(16384, cf->log); if (pool == NULL) { return NGX_CONF_ERROR; } ctx.keys.pool = cf->pool; ctx.keys.temp_pool = pool; if (ngx_hash_keys_array_init(&ctx.keys, NGX_HASH_LARGE) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } ctx.values_hash = ngx_pcalloc(pool, sizeof(ngx_array_t) * ctx.keys.hsize); if (ctx.values_hash == NULL) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } if (ngx_array_init(&ctx.var_values, cf->pool, 2, sizeof(ngx_http_variable_value_t)) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } #if (NGX_PCRE) if (ngx_array_init(&ctx.regexes, cf->pool, 2, sizeof(ngx_http_map_regex_t)) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } #endif ctx.default_value = NULL; ctx.cf = &save; ctx.hostnames = 0; save = *cf; cf->pool = pool; cf->ctx = &ctx; cf->handler = ngx_http_map; cf->handler_conf = conf; rv = ngx_conf_parse(cf, NULL); *cf = save; if (rv != NGX_CONF_OK) { ngx_destroy_pool(pool); return rv; } map->default_value = ctx.default_value ? ctx.default_value: &ngx_http_variable_null_value; hash.key = ngx_hash_key_lc; hash.max_size = mcf->hash_max_size; hash.bucket_size = mcf->hash_bucket_size; hash.name = "map_hash"; hash.pool = cf->pool; if (ctx.keys.keys.nelts) { hash.hash = &map->map.hash.hash; hash.temp_pool = NULL; if (ngx_hash_init(&hash, ctx.keys.keys.elts, ctx.keys.keys.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } } if (ctx.keys.dns_wc_head.nelts) { ngx_qsort(ctx.keys.dns_wc_head.elts, (size_t) ctx.keys.dns_wc_head.nelts, sizeof(ngx_hash_key_t), ngx_http_map_cmp_dns_wildcards); hash.hash = NULL; hash.temp_pool = pool; if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_head.elts, ctx.keys.dns_wc_head.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } map->map.hash.wc_head = (ngx_hash_wildcard_t *) hash.hash; } if (ctx.keys.dns_wc_tail.nelts) { ngx_qsort(ctx.keys.dns_wc_tail.elts, (size_t) ctx.keys.dns_wc_tail.nelts, sizeof(ngx_hash_key_t), ngx_http_map_cmp_dns_wildcards); hash.hash = NULL; hash.temp_pool = pool; if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_tail.elts, ctx.keys.dns_wc_tail.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } map->map.hash.wc_tail = (ngx_hash_wildcard_t *) hash.hash; } #if (NGX_PCRE) if (ctx.regexes.nelts) { map->map.regex = ctx.regexes.elts; map->map.nregex = ctx.regexes.nelts; } #endif ngx_destroy_pool(pool); return rv; } static int ngx_libc_cdecl ngx_http_map_cmp_dns_wildcards(const void *one, const void *two) { ngx_hash_key_t *first, *second; first = (ngx_hash_key_t *) one; second = (ngx_hash_key_t *) two; return ngx_dns_strcmp(first->key.data, second->key.data); } static char * ngx_http_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf) { ngx_int_t rc, index; ngx_str_t *value, file, name; ngx_uint_t i, key; ngx_http_map_conf_ctx_t *ctx; ngx_http_variable_value_t *var, **vp; ctx = cf->ctx; value = cf->args->elts; if (cf->args->nelts == 1 && ngx_strcmp(value[0].data, "hostnames") == 0) { ctx->hostnames = 1; return NGX_CONF_OK; } else if (cf->args->nelts != 2) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid number of the map parameters"); return NGX_CONF_ERROR; } if (ngx_strcmp(value[0].data, "include") == 0) { file = value[1]; if (ngx_conf_full_name(cf->cycle, &file, 1) != NGX_OK) { return NGX_CONF_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_CORE, cf->log, 0, "include %s", file.data); return ngx_conf_parse(cf, &file); } if (value[1].data[0] == '$') { name = value[1]; name.len--; name.data++; index = ngx_http_get_variable_index(ctx->cf, &name); if (index == NGX_ERROR) { return NGX_CONF_ERROR; } var = ctx->var_values.elts; for (i = 0; i < ctx->var_values.nelts; i++) { if (index == (ngx_int_t) var[i].data) { goto found; } } var = ngx_palloc(ctx->keys.pool, sizeof(ngx_http_variable_value_t)); if (var == NULL) { return NGX_CONF_ERROR; } var->valid = 0; var->no_cacheable = 0; var->not_found = 0; var->len = 0; var->data = (u_char *) index; vp = ngx_array_push(&ctx->var_values); if (vp == NULL) { return NGX_CONF_ERROR; } *vp = var; goto found; } key = 0; for (i = 0; i < value[1].len; i++) { key = ngx_hash(key, value[1].data[i]); } key %= ctx->keys.hsize; vp = ctx->values_hash[key].elts; if (vp) { for (i = 0; i < ctx->values_hash[key].nelts; i++) { if (value[1].len != (size_t) vp[i]->len) { continue; } if (ngx_strncmp(value[1].data, vp[i]->data, value[1].len) == 0) { var = vp[i]; goto found; } } } else { if (ngx_array_init(&ctx->values_hash[key], cf->pool, 4, sizeof(ngx_http_variable_value_t *)) != NGX_OK) { return NGX_CONF_ERROR; } } var = ngx_palloc(ctx->keys.pool, sizeof(ngx_http_variable_value_t)); if (var == NULL) { return NGX_CONF_ERROR; } var->len = value[1].len; var->data = ngx_pstrdup(ctx->keys.pool, &value[1]); if (var->data == NULL) { return NGX_CONF_ERROR; } var->valid = 1; var->no_cacheable = 0; var->not_found = 0; vp = ngx_array_push(&ctx->values_hash[key]); if (vp == NULL) { return NGX_CONF_ERROR; } *vp = var; found: if (ngx_strcmp(value[0].data, "default") == 0) { if (ctx->default_value) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate default map parameter"); return NGX_CONF_ERROR; } ctx->default_value = var; return NGX_CONF_OK; } #if (NGX_PCRE) if (value[0].len && value[0].data[0] == '~') { ngx_regex_compile_t rc; ngx_http_map_regex_t *regex; u_char errstr[NGX_MAX_CONF_ERRSTR]; regex = ngx_array_push(&ctx->regexes); if (regex == NULL) { return NGX_CONF_ERROR; } value[0].len--; value[0].data++; ngx_memzero(&rc, sizeof(ngx_regex_compile_t)); if (value[0].data[0] == '*') { value[0].len--; value[0].data++; rc.options = NGX_REGEX_CASELESS; } rc.pattern = value[0]; rc.err.len = NGX_MAX_CONF_ERRSTR; rc.err.data = errstr; regex->regex = ngx_http_regex_compile(ctx->cf, &rc); if (regex->regex == NULL) { return NGX_CONF_ERROR; } regex->value = var; return NGX_CONF_OK; } #endif if (value[0].len && value[0].data[0] == '\\') { value[0].len--; value[0].data++; } rc = ngx_hash_add_key(&ctx->keys, &value[0], var, (ctx->hostnames) ? NGX_HASH_WILDCARD_KEY : 0); if (rc == NGX_OK) { return NGX_CONF_OK; } if (rc == NGX_DECLINED) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid hostname or wildcard \"%V\"", &value[0]); } if (rc == NGX_BUSY) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "conflicting parameter \"%V\"", &value[0]); } return NGX_CONF_ERROR; }