Mercurial > hg > nginx
view src/http/modules/ngx_http_ssi_filter_module.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 | 2d8fab47dd89 |
children | e9a0427f4139 |
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/* * Copyright (C) Igor Sysoev */ #ifndef _NGX_HTTP_SSI_FILTER_H_INCLUDED_ #define _NGX_HTTP_SSI_FILTER_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define NGX_HTTP_SSI_MAX_PARAMS 16 #define NGX_HTTP_SSI_COMMAND_LEN 32 #define NGX_HTTP_SSI_PARAM_LEN 32 #define NGX_HTTP_SSI_PARAMS_N 4 #define NGX_HTTP_SSI_COND_IF 1 #define NGX_HTTP_SSI_COND_ELSE 2 #define NGX_HTTP_SSI_NO_ENCODING 0 #define NGX_HTTP_SSI_URL_ENCODING 1 #define NGX_HTTP_SSI_ENTITY_ENCODING 2 typedef struct { ngx_hash_t hash; ngx_hash_keys_arrays_t commands; } ngx_http_ssi_main_conf_t; typedef struct { ngx_buf_t *buf; u_char *pos; u_char *copy_start; u_char *copy_end; ngx_uint_t key; ngx_str_t command; ngx_array_t params; ngx_table_elt_t *param; ngx_table_elt_t params_array[NGX_HTTP_SSI_PARAMS_N]; ngx_chain_t *in; ngx_chain_t *out; ngx_chain_t **last_out; ngx_chain_t *busy; ngx_chain_t *free; ngx_uint_t state; ngx_uint_t saved_state; size_t saved; size_t looked; size_t value_len; ngx_list_t *variables; ngx_array_t *blocks; unsigned conditional:2; unsigned encoding:2; unsigned block:1; unsigned output:1; unsigned output_chosen:1; ngx_http_request_t *wait; void *value_buf; ngx_str_t timefmt; ngx_str_t errmsg; } ngx_http_ssi_ctx_t; typedef ngx_int_t (*ngx_http_ssi_command_pt) (ngx_http_request_t *r, ngx_http_ssi_ctx_t *ctx, ngx_str_t **); typedef struct { ngx_str_t name; ngx_uint_t index; unsigned mandatory:1; unsigned multiple:1; } ngx_http_ssi_param_t; typedef struct { ngx_str_t name; ngx_http_ssi_command_pt handler; ngx_http_ssi_param_t *params; unsigned conditional:2; unsigned block:1; unsigned flush:1; } ngx_http_ssi_command_t; extern ngx_module_t ngx_http_ssi_filter_module; #endif /* _NGX_HTTP_SSI_FILTER_H_INCLUDED_ */