view auto/os/darwin @ 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 345a014436d4
children d620f497c50f
line wrap: on
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# Copyright (C) Igor Sysoev


have=NGX_DARWIN . auto/have_headers

CORE_INCS="$UNIX_INCS"
CORE_DEPS="$UNIX_DEPS $DARWIN_DEPS"
CORE_SRCS="$UNIX_SRCS $DARWIN_SRCS"



ngx_spacer='
'

# kqueue

echo " + kqueue found"
have=NGX_HAVE_KQUEUE . auto/have
have=NGX_HAVE_CLEAR_EVENT . auto/have
EVENT_MODULES="$EVENT_MODULES $KQUEUE_MODULE"
CORE_SRCS="$CORE_SRCS $KQUEUE_SRCS"
EVENT_FOUND=YES
NGX_KQUEUE_CHECKED=YES

ngx_feature="kqueue's EVFILT_TIMER"
ngx_feature_name="NGX_HAVE_TIMER_EVENT"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/event.h>
                  #include <sys/time.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int      kq;
                  struct kevent    kev;
                  struct timespec  ts;

                  if ((kq = kqueue()) == -1) return 1;

                  kev.ident = 0;
                  kev.filter = EVFILT_TIMER;
                  kev.flags = EV_ADD|EV_ENABLE;
                  kev.fflags = 0;
                  kev.data = 1000;
                  kev.udata = 0;

                  ts.tv_sec = 0;
                  ts.tv_nsec = 0;

                  if (kevent(kq, &kev, 1, &kev, 1, &ts) == -1) return 1;

                  if (kev.flags & EV_ERROR) return 1;"

. auto/feature


ngx_feature="Darwin 64-bit kqueue millisecond timeout bug"
ngx_feature_name=NGX_DARWIN_KEVENT_BUG
ngx_feature_run=bug
ngx_feature_incs="#include <sys/event.h>
                  #include <sys/time.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int  kq;
                  struct kevent    kev;
                  struct timespec  ts;
                  struct timeval   tv, tv0;

                  kq = kqueue();

                  ts.tv_sec = 0;
                  ts.tv_nsec = 999000000;

                  gettimeofday(&tv, 0);
                  kevent(kq, NULL, 0, &kev, 1, &ts);
                  gettimeofday(&tv0, 0);
                  timersub(&tv0, &tv, &tv);

                  if (tv.tv_sec * 1000000 + tv.tv_usec < 900000) return 1;"

. auto/feature


# sendfile()

CC_AUX_FLAGS="$CC_AUX_FLAGS"
ngx_feature="sendfile()"
ngx_feature_name="NGX_HAVE_SENDFILE"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/types.h>
                  #include <sys/socket.h>
                  #include <sys/uio.h>
                  #include <sys/errno.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int s = 0, fd = 1;
                  off_t n; off_t off = 0;
                  n = sendfile(s, fd, off, &n, NULL, 0);
                  if (n == -1 && errno == ENOSYS) return 1"
. auto/feature

if [ $ngx_found = yes ]; then
    have=NGX_HAVE_SENDFILE . auto/have
    CORE_SRCS="$CORE_SRCS $DARWIN_SENDFILE_SRCS"
fi


ngx_feature="atomic(3)"
ngx_feature_name=NGX_DARWIN_ATOMIC
ngx_feature_run=no
ngx_feature_incs="#include <libkern/OSAtomic.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int32_t  lock, n;
                  n = OSAtomicCompareAndSwap32Barrier(0, 1, lock)"
. auto/feature