Mercurial > hg > nginx-quic
view src/core/ngx_rbtree.h @ 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 | 33c2e3c6f02c |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #ifndef _NGX_RBTREE_H_INCLUDED_ #define _NGX_RBTREE_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef ngx_uint_t ngx_rbtree_key_t; typedef ngx_int_t ngx_rbtree_key_int_t; typedef struct ngx_rbtree_node_s ngx_rbtree_node_t; struct ngx_rbtree_node_s { ngx_rbtree_key_t key; ngx_rbtree_node_t *left; ngx_rbtree_node_t *right; ngx_rbtree_node_t *parent; u_char color; u_char data; }; typedef struct ngx_rbtree_s ngx_rbtree_t; typedef void (*ngx_rbtree_insert_pt) (ngx_rbtree_node_t *root, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); struct ngx_rbtree_s { ngx_rbtree_node_t *root; ngx_rbtree_node_t *sentinel; ngx_rbtree_insert_pt insert; }; #define ngx_rbtree_init(tree, s, i) \ ngx_rbtree_sentinel_init(s); \ (tree)->root = s; \ (tree)->sentinel = s; \ (tree)->insert = i void ngx_rbtree_insert(ngx_thread_volatile ngx_rbtree_t *tree, ngx_rbtree_node_t *node); void ngx_rbtree_delete(ngx_thread_volatile ngx_rbtree_t *tree, ngx_rbtree_node_t *node); void ngx_rbtree_insert_value(ngx_rbtree_node_t *root, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); void ngx_rbtree_insert_timer_value(ngx_rbtree_node_t *root, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel); #define ngx_rbt_red(node) ((node)->color = 1) #define ngx_rbt_black(node) ((node)->color = 0) #define ngx_rbt_is_red(node) ((node)->color) #define ngx_rbt_is_black(node) (!ngx_rbt_is_red(node)) #define ngx_rbt_copy_color(n1, n2) (n1->color = n2->color) /* a sentinel must be black */ #define ngx_rbtree_sentinel_init(node) ngx_rbt_black(node) static ngx_inline ngx_rbtree_node_t * ngx_rbtree_min(ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { while (node->left != sentinel) { node = node->left; } return node; } #endif /* _NGX_RBTREE_H_INCLUDED_ */