最近一段时间一直在研究高可用高并发负载均衡分布式集群等技术，先前发布了lvs基于网络第四次协议搭建的小集群，现在用空刚好搭建了一个基于nginx搭建的小集群。
我准备了四台机器，情况如下
分别修改2太子服务器tomcat目录下的webapps/ROOT/index.jsp修改启动的web服务器
vmm02 index.jsp页面修改如下：
<html><body>vmm02 SESSIONID <%=session.getId()%><br><%Integer num=(Integer)session.getAttribute("num");if(num==null){session.setAttribute("num",1);}else{session.setAttribute("num",num+1);}%><%=session.getAttribute("num")%></body></html>
vmm03 index.jsp页面修改如下：
<html><body>vmm03 SESSIONID <%=session.getId()%><br><%Integer num=(Integer)session.getAttribute("num");if(num==null){session.setAttribute("num",1);}else{session.setAttribute("num",num+1);}%><%=session.getAttribute("num")%></body></html>
配置完成后可以分别启动tomcat后查看网页效果。
二.分别在vmm01和vmm04上安装配置nginx(注意2台机器都要配置)
1 安装GCC编译器等工具并编译nginx(我安装的是基于nginx淘宝开发的tengine)
a)yum install gcc openssl-devel pcre-devel zlib-develb)wget /openresty/echo-nginx-module/archive/v0.60.tar.gzc)wget /download/tengine-2.1.2.tar.gzd)tar zxf v0.60.tar.gze)tar zxf tengine-2.1.2.tar.gzf)./configure --add-module=/root/echo-nginx-module-0.60make && make install
2 配置为系统服务
在 /etc/init.d文件夹下添加nginx文件，文件内容脚本如下
****按i键为输入状态后！！！！****
#!/bin/sh## nginx - this script starts and stops the nginx daemon## chkconfig: - 85 15 # description: Nginx is an HTTP(S) server, HTTP(S) reverse \#proxy and IMAP/POP3 proxy server# processname: nginx# config:/etc/nginx/nginx.conf# config:/etc/sysconfig/nginx# pidfile:/var/run/nginx.pid# Source function library.. /etc/rc.d/init.d/functions# Source networking configuration.. /etc/sysconfig/network# Check that networking is up.[ "$NETWORKING" = "no" ] && exit 0##################################### nginx="/usr/local/nginx/sbin/nginx"#####################################prog=$(basename $nginx)#####################################NGINX_CONF_FILE="/usr/local/nginx/conf/nginx.conf"#####################################[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginxlockfile=/var/lock/subsys/nginxmake_dirs() {# make required directoriesuser=`nginx -V 2>&1 | grep "configure arguments:" | sed 's/[^*]*--user=\([^ ]*\).*/\1/g' -`options=`$nginx -V 2>&1 | grep 'configure arguments:'`for opt in $options; doif [ `echo $opt | grep '.*-temp-path'` ]; thenvalue=`echo $opt | cut -d "=" -f 2`if [ ! -d "$value" ]; then# echo "creating" $valuemkdir -p $value && chown -R $user $valuefifidone}start() {[ -x $nginx ] || exit 5[ -f $NGINX_CONF_FILE ] || exit 6make_dirsecho -n $"Starting $prog: "daemon $nginx -c $NGINX_CONF_FILEretval=$?echo[ $retval -eq 0 ] && touch $lockfilereturn $retval}stop() {echo -n $"Stopping $prog: "killproc $prog -QUITretval=$?echo[ $retval -eq 0 ] && rm -f $lockfilereturn $retval}restart() {configtest || return $?stopsleep 1start}reload() {configtest || return $?echo -n $"Reloading $prog: "killproc $nginx -HUPRETVAL=$?echo}force_reload() {restart}configtest() {$nginx -t -c $NGINX_CONF_FILE}rh_status() {status $prog}rh_status_q() {rh_status >/dev/null 2>&1}case "$1" instart)rh_status_q && exit 0$1;;stop)rh_status_q || exit 0$1;;restart|configtest)$1;;reload)rh_status_q || exit 7$1;;force-reload)force_reload;;status)rh_status;;condrestart|try-restart)rh_status_q || exit 0;;*)echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"exit 2esac
添加该内容后可以通过如下命令启动nginx：
service nginx start|stop|reload
如果想配置开机启动可以如下配置
chmod+x nginx
chkconfig –add nginx
chkconfig nginx on
chkconfig –list nginx
3 修改配置文件，默认安装在/usr/local目录下
在/usr/local/nginx/conf目录下修改nginx.conf文件如下:
#user nobody;worker_processes 2;#error_log logs/error.log;#error_log logs/error.log notice;#error_log logs/error.log info;#pid logs/nginx.pid;events {worker_connections 1024;}http {include mime.types;default_type application/octet-stream;#log_format main '$remote_addr - $remote_user [$time_local] "$request" '# '$status $body_bytes_sent "$http_referer" '# '"$http_user_agent" "$http_x_forwarded_for"';#access_log logs/access.log main;sendfile on;#tcp_nopushon;#keepalive_timeout 0;keepalive_timeout 65;#gzip on;upstream tomcat{server 192.168.252.12:8080;server 192.168.252.13:8080;check interval=3000 rise=2 fall=5 timeout=1000 type=http;check_http_send "HEAD / HTTP/1.0\r\n\r\n";check_http_expect_alive http_2xx http_3xx;}server {listen 80;server_name 192.168.252.200;#charset koi8-r;#access_log logs/host.access.log main;location / {proxy_pass http://tomcat;}location /status {check_status;}}}
三.vmm01和vmm02安装及配置keepalived
直接通过yum安装keepalived
yum -y install keepalived
默认配置文件在/etc/keepalived/keepalived.conf
vmm01文件keepalived.conf修改如下:
! Configuration File for keepalivedglobal_defs {router_id LVS_MASTER}vrrp_instance VI_1 {state MASTERinterface eth0virtual_router_id 51priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress { 192.168.252.200}}
vmm02下文件keepalived.conf修改如下：
! Configuration File for keepalivedglobal_defs {router_id LVS_BACKUP}vrrp_instance VI_1 {state BACKUPinterface eth0virtual_router_id 51priority 50advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.252.200}}
四.测试开始
在vmm02和vmm03下分别开启tomcat服务
在vmm01和vmm04下分别开启nginx和keepalived服务
分别关闭vmm01和vmm04上的nginx和keepalived服务可以看到访问虚拟ip依然可以轮询访问tomcat
效果如下:由于我配置了memcache的session同步所以sessionid相同，你们没有配置sessionid会不通的，下次讲哈tomcat
基于memcahe的session同步!!!!
