Mercurial > hg > nginx
view auto/cc/name @ 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 | 4871a7dc12a9 |
| children | 1f908d2dde8d |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. if [ "$NGX_PLATFORM" != win32 ]; then ngx_feature="C compiler" ngx_feature_name= ngx_feature_run=yes ngx_feature_incs= ngx_feature_path= ngx_feature_libs= ngx_feature_test= . auto/feature if [ $ngx_found = no ]; then echo echo $0: error: C compiler $CC is not found echo exit 1 fi fi if [ "$CC" = cl ]; then if `$NGX_WINE $CC -v 2>&1 \ | grep '^Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16' \ >/dev/null 2>&1`; then NGX_CC_NAME=msvc10 echo " + using Microsoft Visual C++ 10 compiler" else if `$NGX_WINE $CC -v 2>&1 \ | grep '^Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 14' \ >/dev/null 2>&1`; then NGX_CC_NAME=msvc8 echo " + using Microsoft Visual C++ 8 compiler" else if `$NGX_WINE $CC -v 2>&1 \ | grep '^Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13' \ >/dev/null 2>&1`; then NGX_CC_NAME=msvc7 echo " + using Microsoft Visual C++ 7 compiler" else NGX_CC_NAME=msvc echo " + using Microsoft Visual C++ compiler" fi fi fi else if [ "$CC" = wcl386 ]; then NGX_CC_NAME=owc echo " + using Open Watcom C compiler" else if [ "$CC" = bcc32 ]; then NGX_CC_NAME=bcc echo " + using Borland C++ compiler" else if `$CC -V 2>&1 | grep '^Intel(R) C' >/dev/null 2>&1`; then NGX_CC_NAME=icc echo " + using Intel C++ compiler" else if `$CC -v 2>&1 | grep 'gcc version' >/dev/null 2>&1`; then NGX_CC_NAME=gcc echo " + using GNU C compiler" else if `$CC -V 2>&1 | grep 'Sun C' >/dev/null 2>&1`; then NGX_CC_NAME=sunc echo " + using Sun C compiler" else if `$CC -V 2>&1 | grep '^Compaq C' >/dev/null 2>&1`; then NGX_CC_NAME=ccc echo " + using Compaq C compiler" else if `$CC -V 2>&1 | grep '^aCC: ' >/dev/null 2>&1`; then NGX_CC_NAME=acc echo " + using HP aC++ compiler" else NGX_CC_NAME=unknown fi # acc fi # ccc fi # sunc fi # icc fi # gcc fi # bcc fi # owc fi # msvc