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nginx+keepalived 高可用兼负载均衡集群
版本
| 作者
| 联系方式
| 最后更新
| v0.3
| purplegrape
| purplegrape4@gmail.com
| 2013-04-10
|
Nginx是一个高性能的web服务器,同时也是一个优秀的反向代理服务器,本文利用两台Dell R720 构建一个高可用兼负载均衡的Linux web集群。
原理
通过nginx分别搭建两个web服务器,监听在本地非80端口;
然后利用nginx构建一个包含两个节点的负载均衡池;
最后通过keepalived实现负载均衡池的高可用。两个节点同时运行时,备用节点可以承载一半的前端流量,一个节点宕机后,负载均衡器通过健康检查,将失效节点踢出集群。
环境:CentOS 6.4 x86_64
软件
| 版本
| nginx
| 1.2.7
| keepalived
| 1.2.7
| php-fpm
| 5.4.13
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主机名
| IP地址
| web01
| 192.168.122.10
| web02
| 192.168.122.20
| VIP
| 192.168.122.30
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安装nginx、keepalived和php-fpm等(编译过程略)
yum install nginx keepalived php-fpm php-gd php-xml php-mysql php-pecl-memcached php-pecl-sphinx watchodg -y
chkconfig nginx on
chkconfig keepalived on
chkconfig php-fpm on
chkconfig watchdog on
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配置nginx
nginx主配置文件 /etc/nginx/nginx.conf
user nginx;
worker_processes 2;
worker_rlimit_nofile 65535;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
use epoll;
worker_connections 2048;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
#access_log /var/log/nginx/access.log main;
sendfile on;
server_tokens off;
#tcp_nopush on;
keepalive_timeout 65;
gzip on;
gzip_static on;
gzip_disable "msie6";
gzip_http_version 1.1;
gzip_vary on;
gzip_comp_level 6;
gzip_proxied any;
gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript application/javascript text/x$
gzip_buffers 16 8k;
client_max_body_size 20m;
client_body_buffer_size 128k;
proxy_hide_header Vary;
proxy_connect_timeout 600;
proxy_read_timeout 600;
proxy_send_timeout 600;
proxy_buffer_size 16k;
proxy_buffers 4 64k;
proxy_busy_buffers_size 128k;
#proxy_temp_file_write_size 128k
proxy_temp_path /dev/shm/tmp;
proxy_cache_path /dev/shm/proxycache/ levels=1:2 keys_zone=shmcache:10m inactive=2h max_size=500m;
include /etc/nginx/conf.d/*.conf;
}
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网站主配置文件/etc/nginx/conf.d/default.conf
upstream webservers {
ip_hash ;
server 192.168.122.10:88 max_fails=3 fail_timeout=3s weight=2 ;
server 192.168.122.20:88 max_fails=3 fail_timeout=3s weight=2 ;
}
server {
listen80 ;
server_name localhost ;
access_log /var/log/nginx/web01.access.log main;
location / {
proxy_redirect off;
proxy_pass http://webservers ;
proxy_cache shmcache;
proxy_cache_valid 200 302 1d;
proxy_cache_valid 404 1h;
proxy_cache_valid any 10m;
proxy_cache_use_stale error timeout invalid_header updating http_500 http_502 http_503 http_504;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_next_upstream error timeout invalid_header http_500 http_502 http_504;
}
location /status {
stub_status on;
access_log off;
allow 192.168.122.0/24;
}
}
server {
listen 192.168.122.10:88;
server_name localhost;
root /usr/share/nginx/html;
indexindex.html index.htm index.php;
#charset koi8-r;
location / {
if (!-e $request_filename) {
rewrite ^/(.*)$ /index.php?q=$1 last;
}
}
#error_page 404 /404.html;
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
#try_files $uri = 404;
fastcgi_pass 127.0.0.1:9000;
#fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_buffer_size 128k;
fastcgi_buffers 256 16k;
fastcgi_busy_buffers_size 256k;
fastcgi_temp_file_write_size 256k;
fastcgi_read_timeout 240;
include fastcgi_params;
}
if ($fastcgi_script_name ~ \..*\/.*php) {
return 403;
}
# deny access to hiden file . (filename begin with ".")
location ~ /\. {
access_log off;
log_not_found off;
deny all;
}
# deny access to bakup file .(any filename end with "~" )
location ~ ~$ {
access_log off;
log_not_found off;
deny all;
}
# cache image file
location ~* \.(jpg|jpeg|gif|png|css|js|ico|xml|swf)$ {
expires 1d;
}
# don't log robots and favion
location = /robots.txt { access_log off; log_not_found off; }
location = /favicon.ico { access_log off; log_not_found off; }
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
location ~ /\.ht {
deny all;
}
}
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配置php-fpm
php-fpm全称php fastcgi process manager,用于管理php的fastcgi进程,自从php5.3.3之后集成进了php源码中。默认的php-fpm用户是apache,我们需要修改成nginx,代码:
sed -i 's/apache/nginx/g' /etc/php-fpm.d/www.conf
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配置keepalived
keepalived是一个高可用软件,通过vrrp心跳来检测对方是否存活。
keepalived主配置文件
global_defs {
notification_email {
root@localhost
}
notification_email_from keepalived01@web01.test.org
smtp_server 127.0.0.1
smtp_connect_timeout 30
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.122.30 label eth0:1
}
}
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配置watchdog
watchdog是个健壮可靠的内核模块,即使在高负载的系统中仍然可以存活。它能够执行检测脚本,定时检查nginx和keepalived进程是否存在,如果不存在可以重新开启进程。
watchdog主配置文件/etc/watchdog.conf
min-memory= 1
repair-binary= /etc/watchdog.d/repair.sh
test-binary = /etc/watchdog.d/test.sh
test-timeout= 5
watchdog-device= /dev/watchdog
admin= root
interval= 10
logtick = 1
realtime= yes
priority= 1
pidfile= /var/run/syslogd.pid
pidfile = /var/run/nginx.pid
pidfile = /var/run/keepalived.pid
pidfile = /var/run/php-fpm/php-fpm.pid
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测试脚本,权限751
#!/usr/bin/env bash
#author:purplegrape
#desc: shell script to check if keepalived/nginx/php-fpm down.
keepalived_proc=`pgrep keepalived |wc -l`
nginx_proc=`pgrep nginx|wc -l`
php_fpm_porc=`pgrep php-fpm|wc -l`
if [$keepalived_proc == 0 ];then
exit 1
fi
if [$nginx_proc == 0 ];then
exit 1
fi
if [$php_fpm_proc == 0 ];then
exit 1
fi
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修复脚本,权限751
#!/usr/bin/env bash
#author:purplegrape
#desc: shell script to repair keepalived/nginx/php-fpm.
keepalived_proc=`pgrep keepalived |wc -l`
nginx_proc=`pgrep nginx|wc -l`
php_fpm_proc=`pgrep php-fpm|wc -l`
if [$keepalived_proc == 0 ];then
wall “keepalived is dead”
/etc/init.d/keepalived restart
sleep 30
/etc/init.d/nginx restart
fi
if [$nginx_proc == 0 ];then
if [$keepalived_proc != 0 ];then
wall “nginx is dead”
/etc/init.d/nginx restart
fi
fi
if [ $php_fpm_proc == 0 ]; then
wall “php-fpm is dead”
/etc/init.d/php-fpm restart
fi
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测试
打开浏览器,访问地址http://192.168.122.30
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