Mercurial > hg > nginx-quic
view src/core/ngx_hash.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 | 4c70bbdfd076 |
children | d620f497c50f |
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/* * Copyright (C) Igor Sysoev */ #ifndef _NGX_HASH_H_INCLUDED_ #define _NGX_HASH_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct { void *value; u_short len; u_char name[1]; } ngx_hash_elt_t; typedef struct { ngx_hash_elt_t **buckets; ngx_uint_t size; } ngx_hash_t; typedef struct { ngx_hash_t hash; void *value; } ngx_hash_wildcard_t; typedef struct { ngx_str_t key; ngx_uint_t key_hash; void *value; } ngx_hash_key_t; typedef ngx_uint_t (*ngx_hash_key_pt) (u_char *data, size_t len); typedef struct { ngx_hash_t hash; ngx_hash_wildcard_t *wc_head; ngx_hash_wildcard_t *wc_tail; } ngx_hash_combined_t; typedef struct { ngx_hash_t *hash; ngx_hash_key_pt key; ngx_uint_t max_size; ngx_uint_t bucket_size; char *name; ngx_pool_t *pool; ngx_pool_t *temp_pool; } ngx_hash_init_t; #define NGX_HASH_SMALL 1 #define NGX_HASH_LARGE 2 #define NGX_HASH_LARGE_ASIZE 16384 #define NGX_HASH_LARGE_HSIZE 10007 #define NGX_HASH_WILDCARD_KEY 1 #define NGX_HASH_READONLY_KEY 2 typedef struct { ngx_uint_t hsize; ngx_pool_t *pool; ngx_pool_t *temp_pool; ngx_array_t keys; ngx_array_t *keys_hash; ngx_array_t dns_wc_head; ngx_array_t *dns_wc_head_hash; ngx_array_t dns_wc_tail; ngx_array_t *dns_wc_tail_hash; } ngx_hash_keys_arrays_t; typedef struct { ngx_uint_t hash; ngx_str_t key; ngx_str_t value; u_char *lowcase_key; } ngx_table_elt_t; void *ngx_hash_find(ngx_hash_t *hash, ngx_uint_t key, u_char *name, size_t len); void *ngx_hash_find_wc_head(ngx_hash_wildcard_t *hwc, u_char *name, size_t len); void *ngx_hash_find_wc_tail(ngx_hash_wildcard_t *hwc, u_char *name, size_t len); void *ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key, u_char *name, size_t len); ngx_int_t ngx_hash_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts); ngx_int_t ngx_hash_wildcard_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts); #define ngx_hash(key, c) ((ngx_uint_t) key * 31 + c) ngx_uint_t ngx_hash_key(u_char *data, size_t len); ngx_uint_t ngx_hash_key_lc(u_char *data, size_t len); ngx_uint_t ngx_hash_strlow(u_char *dst, u_char *src, size_t n); ngx_int_t ngx_hash_keys_array_init(ngx_hash_keys_arrays_t *ha, ngx_uint_t type); ngx_int_t ngx_hash_add_key(ngx_hash_keys_arrays_t *ha, ngx_str_t *key, void *value, ngx_uint_t flags); #endif /* _NGX_HASH_H_INCLUDED_ */