view auto/types/sizeof @ 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 400711951595
children d620f497c50f
line wrap: on
line source


# Copyright (C) Igor Sysoev


echo $ngx_n "checking for $ngx_type size ...$ngx_c"

cat << END >> $NGX_AUTOCONF_ERR

----------------------------------------
checking for $ngx_type size

END

ngx_size=

cat << END > $NGX_AUTOTEST.c

#include <sys/types.h>
#include <sys/time.h>
$NGX_INCLUDE_UNISTD_H
#include <signal.h>
#include <sys/resource.h>
$NGX_INCLUDE_INTTYPES_H
$NGX_INCLUDE_AUTO_CONFIG_H

int main() {
    printf("%d", sizeof($ngx_type));
    return 0;
}

END


ngx_test="$CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
          -o $NGX_AUTOTEST $NGX_AUTOTEST.c $NGX_LD_OPT $ngx_feature_libs"

eval "$ngx_test >> $NGX_AUTOCONF_ERR 2>&1"


if [ -x $NGX_AUTOTEST ]; then
    ngx_size=`$NGX_AUTOTEST`
    echo " $ngx_size bytes"
fi


rm -f $NGX_AUTOTEST


case $ngx_size in
    4)
        if [ "$ngx_type"="long" ]; then
            ngx_max_value=2147483647L
        else
            ngx_max_value=2147483647
        fi

        ngx_max_len='(sizeof("-2147483648") - 1)'
    ;;

    8)
        if [ "$ngx_type"="long long" ]; then
            ngx_max_value=9223372036854775807LL
        else
            ngx_max_value=9223372036854775807L
        fi

        ngx_max_len='(sizeof("-9223372036854775808") - 1)'
    ;;

    *)
        echo
        echo "$0: error: can not detect $ngx_type size"

        echo "----------"    >> $NGX_AUTOCONF_ERR
        cat $NGX_AUTOTEST.c  >> $NGX_AUTOCONF_ERR
        echo "----------"    >> $NGX_AUTOCONF_ERR
        echo $ngx_test       >> $NGX_AUTOCONF_ERR
        echo "----------"    >> $NGX_AUTOCONF_ERR

        exit 1
esac