view src/core/ngx_config.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 df2ae4bc7415
children d620f497c50f
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/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_CONFIG_H_INCLUDED_
#define _NGX_CONFIG_H_INCLUDED_


#include <ngx_auto_headers.h>


#if defined __DragonFly__ && !defined __FreeBSD__
#define __FreeBSD__        4
#define __FreeBSD_version  480101
#endif


#if (NGX_FREEBSD)
#include <ngx_freebsd_config.h>


#elif (NGX_LINUX)
#include <ngx_linux_config.h>


#elif (NGX_SOLARIS)
#include <ngx_solaris_config.h>


#elif (NGX_DARWIN)
#include <ngx_darwin_config.h>


#elif (NGX_WIN32)
#include <ngx_win32_config.h>


#else /* POSIX */
#include <ngx_posix_config.h>

#endif


#ifndef NGX_HAVE_SO_SNDLOWAT
#define NGX_HAVE_SO_SNDLOWAT     1
#endif


#if !(NGX_WIN32)

#define ngx_signal_helper(n)     SIG##n
#define ngx_signal_value(n)      ngx_signal_helper(n)

#define ngx_random               random

/* TODO: #ifndef */
#define NGX_SHUTDOWN_SIGNAL      QUIT
#define NGX_TERMINATE_SIGNAL     TERM
#define NGX_NOACCEPT_SIGNAL      WINCH
#define NGX_RECONFIGURE_SIGNAL   HUP

#if (NGX_LINUXTHREADS)
#define NGX_REOPEN_SIGNAL        INFO
#define NGX_CHANGEBIN_SIGNAL     XCPU
#else
#define NGX_REOPEN_SIGNAL        USR1
#define NGX_CHANGEBIN_SIGNAL     USR2
#endif

#define ngx_cdecl
#define ngx_libc_cdecl

#endif

typedef intptr_t        ngx_int_t;
typedef uintptr_t       ngx_uint_t;
typedef intptr_t        ngx_flag_t;


#define NGX_INT32_LEN   sizeof("-2147483648") - 1
#define NGX_INT64_LEN   sizeof("-9223372036854775808") - 1

#if (NGX_PTR_SIZE == 4)
#define NGX_INT_T_LEN   NGX_INT32_LEN
#else
#define NGX_INT_T_LEN   NGX_INT64_LEN
#endif


#ifndef NGX_ALIGNMENT
#define NGX_ALIGNMENT   sizeof(unsigned long)    /* platform word */
#endif

#define ngx_align(d, a)     (((d) + (a - 1)) & ~(a - 1))
#define ngx_align_ptr(p, a)                                                   \
    (u_char *) (((uintptr_t) (p) + ((uintptr_t) a - 1)) & ~((uintptr_t) a - 1))


#define ngx_abort       abort


/* TODO: platform specific: array[NGX_INVALID_ARRAY_INDEX] must cause SIGSEGV */
#define NGX_INVALID_ARRAY_INDEX 0x80000000


/* TODO: auto_conf: ngx_inline   inline __inline __inline__ */
#ifndef ngx_inline
#define ngx_inline      inline
#endif

#ifndef INADDR_NONE  /* Solaris */
#define INADDR_NONE  ((unsigned int) -1)
#endif

#ifdef MAXHOSTNAMELEN
#define NGX_MAXHOSTNAMELEN  MAXHOSTNAMELEN
#else
#define NGX_MAXHOSTNAMELEN  256
#endif


#if ((__GNU__ == 2) && (__GNUC_MINOR__ < 8))
#define NGX_MAX_UINT32_VALUE  (uint32_t) 0xffffffffLL
#else
#define NGX_MAX_UINT32_VALUE  (uint32_t) 0xffffffff
#endif

#define NGX_MAX_INT32_VALUE   (uint32_t) 0x7fffffff


#endif /* _NGX_CONFIG_H_INCLUDED_ */