nginx+keepalived主辅切换

以前写过一篇，nginx+keepalived 双机互备的文章，写那篇文章的时候没有想过如果apache或者nginx 挂了，而 keepalived 或者 机器没有死，那么主辅是不会切换的，今天就研究了一下该如何监控 nginx进程呢，看官方站看到了。vrrp_script 功能，但是用他的方法实在形不通，可能是我的方法不对，或者是个BUG。所以后来我自己写了个小脚本来完成工作。 环境

Server 1 : ubuntu-server 8.04.4 192.168.6.162 Server 2 : userver-server 8.04.4 192.168.6.188 软件

Keepalived 1.1.15 nginx-0.8.35 pcre-8.02

1.分别在两台服务器上安装nginx 装nginx

tar jxvf pcre-8.02.tar.bz2 cd pcre-8.02

./configure --prefix=/usr --enable-utf8 --enable-pcregrep-libbz2 --enable-pcregrep-libz make

make install

tar zxvf nginx-0.8.35.tar.gz cd nginx-0.8.35

--prefix=/usr/local/nginx --with-pcre --user=www --group=www --with-file-aio --with-http_ssl_module --with-http_flv_module --with-http_gzip_static_module --with-http_stub_status_module --with-cc-opt=' -O3' make

make install

2.分别在两台服务器编写配置文件

vim /usr/local/nginx/conf/nginx.conf user www www;

worker_processes 1;

error_log logs/error.log notice; pid logs/nginx.pid; events {

worker_connections 1024; }

http {

include mime.types;

default_type application/octet-stream; sendfile on; tcp_nopush on; keepalive_timeout 65; gzip on; server {

listen 80;

server_name localhost;

index index.html index.htm; root /var/www;

error_page 500 502 503 504 /50x.html; location = /50x.html { root html; } } }

3.分别在两台机器创建测试文件

echo \> /var/www/index.html echo \> /var/www/index.html

4.安装 keepalived

5.在server 1服务器编写配置文件

vrrp_script chk_http_port {

script \###监控脚本 interval 2 ###监控时间

weight 2 ###目前搞不清楚 }

vrrp_instance VI_1 {

state MASTER ### 设置为 主 interface eth0 ### 监控网卡

virtual_router_id 51 ### 这个两台服务器必须一样

priority 101 ### 权重值 MASTRE 一定要高于 BAUCKUP

authentication {

auth_type PASS ### 加密

auth_pass eric ### 加密的密码，两台服务器一定要一样，不然会出错 }

track_script {

chk_http_port ### 执行监控的服务 }

virtual_ipaddress {

192.168.6.7 ### VIP 地址 } }

apt-get install keepalived

6.在 server 2 服务器 keepalived 配置

vrrp_script chk_http_port {

script \ interval 2 weight 2 }

vrrp_instance VI_1 {

state BACKUP ### 设置为 辅机 interface eth0

virtual_router_id 51 ### 与 MASTRE 设置 值一样 priority 100 ### 比 MASTRE权重值 低 authentication {

auth_type PASS

auth_pass eric ### 密码 与 MASTRE 一样 }

track_script {

chk_http_port }

virtual_ipaddress { 192.168.6.7 } }

7.编写监控nginx监控脚本

vim /opt/nginx_pid.sh #!/bin/bash # varsion 0.0.2

# 根据一网友说这样做不科学，如果nginx服务起来了，但是我把keepalived 杀掉了，我的理由是，如果nginx死掉了，我觉得就很难在起来，再有就是nagios 当然要给你报警了啊。不过这位同学说的有道理，所以就稍加改了一下脚本

A=`ps -C nginx --no-header |wc -l` ## 查看是否有 nginx进程 把值赋给变量A

if [ $A -eq 0 ];then ## 如果没有进程值得为 零 /usr/local/nginx/sbin/nginx sleep 3

if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then

killall keepalived ## 则结束 keepalived 进程 fi fi

8、测试,分别在两个服务器 启动 nginx 和 keepalived

/usr/local/nginx/sbin/nginx /etc/init.d/keepalived start

监控 server 1 的日志

Apr 20 18:37:39 nginx Keepalived_vrrp: Registering Kernel netlink command channel

Apr 20 18:37:39 nginx Keepalived_vrrp: Registering gratutious ARP shared channel

Apr 20 18:37:39 nginx Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'.

Apr 20 18:37:39 nginx Keepalived_healthcheckers: Opening file '/etc/keepalived/keepalived.conf'.

Apr 20 18:37:39 nginx Keepalived_healthcheckers: Configuration is using : 3401 Bytes

Apr 20 18:37:39 nginx Keepalived_vrrp: Configuration is using : 35476 Bytes Apr 20 18:37:40 nginx Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE

Apr 20 18:37:41 nginx Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE

Apr 20 18:37:41 nginx Keepalived_vrrp: Netlink: skipping nl_cmd msg...

Apr 20 18:37:41 nginx Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded

监控 server 2的日志

Apr2018:38:23 varnish Keepalived_healthcheckers: Opening file '/etc/keepalived/keepalived.conf'.

Apr 20 18:38:23 varnish Keepalived_healthcheckers: Configuration is using : 3

405 Bytes

Apr 20 18:38:23 varnish Keepalived_vrrp: Using MII-BMSR NIC polling thread...

Apr 20 18:38:23 varnish Keepalived_vrrp: Registering Kernel netlink reflector Apr 20 18:38:23 varnish Keepalived_vrrp: Registering Kernel netlink command channel

Apr 20 18:38:23 varnish Keepalived_vrrp: Registering gratutious ARP shared channel

Apr 20 18:38:23 varnish Keepalived_vrrp: Opening file '/etc/keepalived/keepalived.conf'.

Apr 20 18:38:23 varnish Keepalived_vrrp: Configuration is using : 35486 Bytes

Apr 20 18:38:23 varnish Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE

Apr 20 18:38:25 varnish Keepalived_vrrp: VRRP_Script(chk_http_port) succeeded

看日志可以看出，两台服务器的 MASTRE 和 BACUKUP 已经都正常了 现在我们在 server 1 把 nginx 服务器停到

Server 1 $> killall nginx

这时候看server 1的日志

Apr 20 18:41:26 nginx Keepalived_healthcheckers: Terminating Healthchecker child process on signal

Apr 20 18:41:26 nginx Keepalived_vrrp: Terminating VRRP child process on signal

可以看出keepalived 的进程已经停到

这时候看server 2的日志，看是否已经接管

Apr 20 18:41:23 varnish Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE

Apr 20 18:41:24 varnish Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE

Apr 20 18:41:24 varnish Keepalived_vrrp: Netlink: skipping nl_cmd msg...

很明显的看出 server 2 已经接管了，已经变为 MASTER 了

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