Mercurial > hg > nginx
view auto/cc/owc @ 4621:c90801720a0c
Upstream: smooth weighted round-robin balancing.
For edge case weights like { 5, 1, 1 } we now produce { a, a, b, a, c, a, a }
sequence instead of { c, b, a, a, a, a, a } produced previously.
Algorithm is as follows: on each peer selection we increase current_weight
of each eligible peer by its weight, select peer with greatest current_weight
and reduce its current_weight by total number of weight points distributed
among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of
current_weight's:
a b c
0 0 0 (initial state)
5 1 1 (a selected)
-2 1 1
3 2 2 (a selected)
-4 2 2
1 3 3 (b selected)
1 -4 3
6 -3 4 (a selected)
-1 -3 4
4 -2 5 (c selected)
4 -2 -2
9 -1 -1 (a selected)
2 -1 -1
7 0 0 (a selected)
0 0 0
To preserve weight reduction in case of failures the effective_weight
variable was introduced, which usually matches peer's weight, but is
reduced temporarily on peer failures.
This change also fixes loop with backup servers and proxy_next_upstream
http_404 (ticket #47), and skipping alive upstreams in some cases if there
are multiple dead ones (ticket #64).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 14 May 2012 09:57:20 +0000 |
parents | d620f497c50f |
children | 670ceaba03d8 |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. # Open Watcom C 1.0, 1.2, 1.3 # optimizations # maximize speed CFLAGS="$CFLAGS -ot" # reorder instructions for best pipeline usage CFLAGS="$CFLAGS -op" # inline intrinsic functions CFLAGS="$CFLAGS -oi" # inline expansion CFLAGS="$CFLAGS -oe" # disable stack checking calls CFLAGS="$CFLAGS -s" case $CPU in pentium) # optimize for Pentium and Athlon # register-based arguments passing conventions CPU_OPT="-5r" # stack-based arguments passing conventions #CPU_OPT="-5s" ;; pentiumpro) # optimize for Pentium Pro, Pentium II and Pentium III # register-based arguments passing conventions CPU_OPT="-6r" # stack-based arguments passing conventions #CPU_OPT="-6s" ;; esac CFLAGS="$CFLAGS $CPU_OPT" # warnings # maximum level CFLAGS="$CFLAGS -wx" #CFLAGS="$CFLAGS -w3" # stop on warning CFLAGS="$CFLAGS -we" # built target is NT CFLAGS="$CFLAGS -bt=nt" # multithreaded CFLAGS="$CFLAGS -bm" # debug CFLAGS="$CFLAGS -d2" # quiet CFLAGS="$CFLAGS -zq" # Open Watcom C 1.2 have=NGX_HAVE_C99_VARIADIC_MACROS . auto/have # the precompiled headers CORE_DEPS="$CORE_DEPS $NGX_OBJS/ngx_config.pch" NGX_PCH="$NGX_OBJS/ngx_config.pch" NGX_BUILD_PCH="-fhq=$NGX_OBJS/ngx_config.pch" NGX_USE_PCH="-fh=$NGX_OBJS/ngx_config.pch" # the link flags, built target is NT GUI mode application #CORE_LINK="$CORE_LINK -l=nt_win" # the resource file NGX_RCC="wrc \$(CORE_INCS) -fo=$NGX_OBJS/nginx.res " NGX_RCC="$NGX_RCC $NGX_WIN32_RC $NGX_OBJS/nginx.exe" ngx_include_opt="-i=" ngx_objout="-fo" ngx_binout="-fe=" ngx_objext="obj" ngx_binext=".exe" ngx_regex_dirsep='\\' ngx_dirsep="\\" ngx_long_start=' ' ngx_long_end=' ' ngx_long_regex_cont=' \&\ ' ngx_long_cont=' & ' ngx_regex_cont=' \&\ ' ngx_cont=' & ' ngx_tab=' & '