Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_random_index_module.c @ 4622:0dfdc3f732cb
Upstream: fixed ip_hash rebalancing with the "down" flag.
Due to weight being set to 0 for down peers, order of peers after sorting
wasn't the same as without the "down" flag (with down peers at the end),
resulting in client rebalancing for clients on other servers. The only
rebalancing which should happen after adding "down" to a server is one
for clients on the server.
The problem was introduced in r1377 (which fixed endless loop by setting
weight to 0 for down servers). The loop is no longer possible with new
smooth algorithm, so preserving original weight is safe.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 14 May 2012 09:58:07 +0000 |
parents | 778ef9c3fd2d |
children | 47daf95d0138 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_flag_t enable; } ngx_http_random_index_loc_conf_t; #define NGX_HTTP_RANDOM_INDEX_PREALLOCATE 50 static ngx_int_t ngx_http_random_index_error(ngx_http_request_t *r, ngx_dir_t *dir, ngx_str_t *name); static ngx_int_t ngx_http_random_index_init(ngx_conf_t *cf); static void *ngx_http_random_index_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_random_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_command_t ngx_http_random_index_commands[] = { { ngx_string("random_index"), NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_random_index_loc_conf_t, enable), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_random_index_module_ctx = { NULL, /* preconfiguration */ ngx_http_random_index_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_random_index_create_loc_conf, /* create location configuration */ ngx_http_random_index_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_random_index_module = { NGX_MODULE_V1, &ngx_http_random_index_module_ctx, /* module context */ ngx_http_random_index_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_random_index_handler(ngx_http_request_t *r) { u_char *last, *filename; size_t len, allocated, root; ngx_err_t err; ngx_int_t rc; ngx_str_t path, uri, *name; ngx_dir_t dir; ngx_uint_t n, level; ngx_array_t names; ngx_http_random_index_loc_conf_t *rlcf; if (r->uri.data[r->uri.len - 1] != '/') { return NGX_DECLINED; } if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD|NGX_HTTP_POST))) { return NGX_DECLINED; } rlcf = ngx_http_get_module_loc_conf(r, ngx_http_random_index_module); if (!rlcf->enable) { return NGX_DECLINED; } #if (NGX_HAVE_D_TYPE) len = NGX_DIR_MASK_LEN; #else len = NGX_HTTP_RANDOM_INDEX_PREALLOCATE; #endif last = ngx_http_map_uri_to_path(r, &path, &root, len); if (last == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } allocated = path.len; path.len = last - path.data - 1; path.data[path.len] = '\0'; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http random index: \"%s\"", path.data); if (ngx_open_dir(&path, &dir) == NGX_ERROR) { err = ngx_errno; if (err == NGX_ENOENT || err == NGX_ENOTDIR || err == NGX_ENAMETOOLONG) { level = NGX_LOG_ERR; rc = NGX_HTTP_NOT_FOUND; } else if (err == NGX_EACCES) { level = NGX_LOG_ERR; rc = NGX_HTTP_FORBIDDEN; } else { level = NGX_LOG_CRIT; rc = NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_log_error(level, r->connection->log, err, ngx_open_dir_n " \"%s\" failed", path.data); return rc; } if (ngx_array_init(&names, r->pool, 32, sizeof(ngx_str_t)) != NGX_OK) { return ngx_http_random_index_error(r, &dir, &path); } filename = path.data; filename[path.len] = '/'; for ( ;; ) { ngx_set_errno(0); if (ngx_read_dir(&dir) == NGX_ERROR) { err = ngx_errno; if (err != NGX_ENOMOREFILES) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, err, ngx_read_dir_n " \"%V\" failed", &path); return ngx_http_random_index_error(r, &dir, &path); } break; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http random index file: \"%s\"", ngx_de_name(&dir)); if (ngx_de_name(&dir)[0] == '.') { continue; } len = ngx_de_namelen(&dir); if (dir.type == 0 || ngx_de_is_link(&dir)) { /* 1 byte for '/' and 1 byte for terminating '\0' */ if (path.len + 1 + len + 1 > allocated) { allocated = path.len + 1 + len + 1 + NGX_HTTP_RANDOM_INDEX_PREALLOCATE; filename = ngx_pnalloc(r->pool, allocated); if (filename == NULL) { return ngx_http_random_index_error(r, &dir, &path); } last = ngx_cpystrn(filename, path.data, path.len + 1); *last++ = '/'; } ngx_cpystrn(last, ngx_de_name(&dir), len + 1); if (ngx_de_info(filename, &dir) == NGX_FILE_ERROR) { err = ngx_errno; if (err != NGX_ENOENT) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, err, ngx_de_info_n " \"%s\" failed", filename); return ngx_http_random_index_error(r, &dir, &path); } if (ngx_de_link_info(filename, &dir) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno, ngx_de_link_info_n " \"%s\" failed", filename); return ngx_http_random_index_error(r, &dir, &path); } } } if (!ngx_de_is_file(&dir)) { continue; } name = ngx_array_push(&names); if (name == NULL) { return ngx_http_random_index_error(r, &dir, &path); } name->len = len; name->data = ngx_pnalloc(r->pool, len); if (name->data == NULL) { return ngx_http_random_index_error(r, &dir, &path); } ngx_memcpy(name->data, ngx_de_name(&dir), len); } if (ngx_close_dir(&dir) == NGX_ERROR) { ngx_log_error(NGX_LOG_ALERT, r->connection->log, ngx_errno, ngx_close_dir_n " \"%s\" failed", &path); } n = names.nelts; if (n == 0) { return NGX_DECLINED; } name = names.elts; n = (ngx_uint_t) (((uint64_t) ngx_random() * n) / 0x80000000); uri.len = r->uri.len + name[n].len; uri.data = ngx_pnalloc(r->pool, uri.len); if (uri.data == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } last = ngx_copy(uri.data, r->uri.data, r->uri.len); ngx_memcpy(last, name[n].data, name[n].len); return ngx_http_internal_redirect(r, &uri, &r->args); } static ngx_int_t ngx_http_random_index_error(ngx_http_request_t *r, ngx_dir_t *dir, ngx_str_t *name) { if (ngx_close_dir(dir) == NGX_ERROR) { ngx_log_error(NGX_LOG_ALERT, r->connection->log, ngx_errno, ngx_close_dir_n " \"%V\" failed", name); } return NGX_HTTP_INTERNAL_SERVER_ERROR; } static void * ngx_http_random_index_create_loc_conf(ngx_conf_t *cf) { ngx_http_random_index_loc_conf_t *conf; conf = ngx_palloc(cf->pool, sizeof(ngx_http_random_index_loc_conf_t)); if (conf == NULL) { return NULL; } conf->enable = NGX_CONF_UNSET; return conf; } static char * ngx_http_random_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_random_index_loc_conf_t *prev = parent; ngx_http_random_index_loc_conf_t *conf = child; ngx_conf_merge_value(conf->enable, prev->enable, 0); return NGX_CONF_OK; } static ngx_int_t ngx_http_random_index_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_CONTENT_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_random_index_handler; return NGX_OK; }