环境说明：
nginx1: 192.168.2.47 nginx2: 192.168.2.48 tomcat1: 192.168.2.49 tomcat2: 192.168.2.50 vip: 192.168.2.51
一.Nginx配置
1.安装Nginx所需pcre库
wget ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.10.tar.gz
tar - zxvf pcre- 8.10 .tar .gz cd pcre- 8.10 ./ configure make make install
2.安装Nginx
wget http://nginx.org/download/nginx-0.8.52.tar.gz
groupadd www useradd - g www www tar zxvf nginx- 0.8.52.tar .gz cd nginx- 0.8.52/ ./ configure -- user= www -- group= www -- prefix=/ usr/ local/ nginx -- with- http_stub_status_module -- with- http_ssl_module make make install
注：如果出现以下错误
./ configure: error: SSL modules require the OpenSSL library. Centos 需要安装openssl- devel Ubuntu则需要安装: sudo apt- get install libssl- dev
3.修改配置文件为以下内容：
user? www www; worker_processes 2 ; pid??????? logs/ nginx.pid ; worker_rlimit_nofile 51200 ; ? events { use epoll; worker_connections 51200 ; } ? http { include?????? mime.types ; default_type? application/ octet- stream; keepalive_timeout 120 ; server_tokens off; send_timeout 60 ; tcp_nodelay on; ? upstream? tomcats? { server 192.168.2.50: 8080 ; server 192.168.2.49: 8080 ; #ip_hash; ?????? #在没有做共享session的情况下ip_hash可以解决session问题 ? } ? server { listen? 80 ; server_name? 192.168.2.48; ? location / { proxy_pass??????? http: //tomcats; proxy_set_header?? Host???????????? $host; proxy_set_header?? X- Real- IP??????? $remote_addr; proxy_set_header?? X- Forwarded- For ? $proxy_add_x_forwarded_for; } ? log_format access_log? '$remote_addr - $remote_user [$time_local] $request ' '"$status" $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"' ; access_log? / usr/ local/ nginx/ logs/ access.log ? access_log; } ? }
4.测试配置文件
/ usr/ local/ nginx/ sbin/ nginx - t
如果出现以下情况
/ usr/ local/ nginx/ sbin/ nginx: error while loading shared libraries: libpcre.so .0: or directory
解决方法：
sudo ln - s / usr/ local/ lib/ libpcre.so .0 / usr/ lib/ libpcre.so .0
/usr/local/nginx/sbin/nginx -t
显示以下信息为正确的
the configuration file / usr/ local/ nginx/ conf/ nginx.conf syntax is ok configuration file / usr/ local/ nginx/ conf/ nginx.conf test is successful
5.优化内核参数
vim /etc/sysctl.conf在最后添加
net.ipv4 .tcp_max_syn_backlog = 65536 net.core .netdev_max_backlog = 32768 net.core .somaxconn = 32768 net.core .wmem_default = 8388608 net.core .rmem_default = 8388608 net.core .rmem_max = 16777216 net.core .wmem_max = 16777216 net.ipv4 .tcp_timestamps = 0 net.ipv4 .tcp_synack_retries = 2 net.ipv4 .tcp_syn_retries = 2 net.ipv4 .tcp_tw_recycle = 1 net.ipv4 .tcp_tw_reuse = 1 net.ipv4 .tcp_mem = 94500000 915000000 927000000 net.ipv4 .tcp_max_orphans = 3276800 net.ipv4 .ip_local_port_range = 1024 ? 65535
保存退出后执行
sysctl -
p
6.切割Nginx日志脚本
#!/ bin/ bash PATH_LOGS= "/usr/local/nginx/logs" YEAR= `date - d "-1 days" + "%Y" ` MONTH= `date - d "-1 days" + "%m" ` mkdir - p $PATH_LOGS/ $YEAR/ $MONTH mv $PATH_LOGS/ access.log $PATH_LOGS/ $YEAR/ $MONTH/ access_$( date - d "-1 days" + "%Y%m%d" ) .log kill - USR1 `cat $PATH_LOGS/ nginx.pid `
把该脚本加到crontab每天00点执行
注：备机的Nginx和以上安装步骤一样
二.安装配置Keepalived
1.下载所需要的软件
wget http://keepalived.org/software/keepalived-1.1.19.tar.gz
wget http://rpm5.org/files/popt/popt-1.16.tar.gz
2.安装popt
编译keepalived时需要popt，否则会报以下错误：
configure: error: Popt libraries is required
tar - zxvf popt- 1.16 .tar .gz cd popt- 1.16 ./ configure make make install
3.安装keepalived
tar - zxvf keepalived- 1.1.19.tar .gz cd keepalived- 1.1.19 ./ configure -- prefix=/ usr/ local/ keepalived make make install
4.修改配置文件为以下内容:
vim /usr/local/keepalived/etc/keepalived/keepalived.conf
! Configuration File for keepalived ? global_defs { router_id LVS_DEVEL } vrrp_script Monitor_Nginx { script "/root/scripts/monitor_nginx.sh" #根据自己的实际路径放置monitor_nginx.sh ??? interval 2 weight 2 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1234 } track_script { Monitor_Nginx } virtual_ipaddress { 192.168.2.51 } }
注：monitor_nginx.sh为监控nginx进程的脚本,内容如下
#!/ bin/ bash if [ "$(ps -ef | grep " nginx: master process"| grep -v grep )" == "" ] then / usr/ local/ nginx/ sbin/ nginx sleep 5 if [ "$(ps -ef | grep " nginx: master process"| grep -v grep )" == "" ] then killall keepalived fi fi
5.启动keepalived
/ usr/ local/ keepalived/ sbin/ keepalived - D - f / usr/ local/ keepalived/ etc/ keepalived/ keepalived.conf
注:备机的keepalived的安装和上面一样，只要把配置文件改为以下(把MASTER改为BACKUP)
! Configuration File for keepalived ? global_defs { router_id LVS_DEVEL } vrrp_script Monitor_Nginx { script "/root/scripts/monitor_nginx.sh" interval 2 weight 2 } vrrp_instance VI_1 { state BACKUP??????????? #改为BACKUP interface eth0 virtual_router_id 51 priority 100 ??????????? #比MASTER数值要低 advert_int 1 authentication { auth_type PASS auth_pass 1234 } track_script { Monitor_Nginx } virtual_ipaddress { 192.168.2.51 } }
三．测试步骤
1．?? ?访问VIP看是否能够正常访问后端的tomcat
2．?? ?停止其中一个tomcat看是否能将访问转到另一台上
3．?? ?停止两台nginx上任何一个nginx进程看监控进程脚本是否会自动启动nginx
4．?? ?停止任何一台nginx上的keepalived进程看另一台是否接管vip
比如停止Master上的keepalived,例如如下killall keepalived,查看BACKUP机器是否已经接管，如果BACKUP接管后，BACKUP机器日志会是出下情况
tail? /var/log/syslog
Keepalived_vrrp: VRRP_Instance( VI_1) Transition to MASTER STATE Keepalived_vrrp: VRRP_Instance( VI_1) Entering MASTER STATE Keepalived_vrrp: VRRP_Instance( VI_1) setting protocol VIPs. Keepalived_vrrp : VRRP_Instance( VI_1) Sending gratuitous ARPs on eth0 for 192.168.2.51
MASTER机器上日志会显示
Keepalived_vrrp: Terminating VRRP child process on signal Keepalived_vrrp: VRRP_Instance( VI_1) removing protocol VIPs.
现在把MASTER上的Keepalived重新启动，会看到MASTER重新接管VIP，并对外提供服务，BACKUP仍旧回到BACKUP STATE,如果不是这种情况，请检查配置文件和步骤.
现在的BACKUP日志如下：
Keepalived_vrrp: VRRP_Instance( VI_1) Received higher prio advert Keepalived_vrrp: VRRP_Instance( VI_1) Entering BACKUP STATE Keepalived_vrrp: VRRP_Instance( VI_1) removing protocol VIPs.
Master日志如下：
Keepalived_vrrp: VRRP_Script( Monitor_Nginx) succeeded Keepalived_vrrp: VRRP_Instance( VI_1) Transition to MASTER STATE Keepalived_vrrp: VRRP_Instance( VI_1) Entering MASTER STATE Keepalived_vrrp: VRRP_Instance( VI_1) setting protocol VIPs. Keepalived_vrrp : VRRP_Instance( VI_1) Sending gratuitous ARPs on eth0 for 192.168.2.51