集群搭建tomcat+keepalived+nginx+memcached
一、基础知识
1、linux基本命令
ps -aux | grep tomcat
ps -aux | grep java
ps -aux | grep pid
netstat -anp |grep portno即：netstat –apn | grep 8080
centos版本差异命令有区别，如启动服务：
Centos7：systemctlrestart iptables.service
Centos6：service iptablesrestart
二、架构图
说明：
三、安装配置
1、安装nginx
1.1、需要编译程序依赖包
yum install gcc gcc-c++ make automake autoconflibtool pcre pcre-devel zlib zlib-devel openssl openssl-devel
1.2、安装配置
192.168.117.131和192.168.117.132机器上安装nginx
下载nginx包:wgethttp://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
建立nginx的yum仓库：rpm -ivh nginx-release-centos-7-0.el7.ngx.noarch.rpm
安装：yum install nginx
查看：whereis nginx
检查：/usr/sbin/nginx –t检查安装是否成功
启动：systemctl start nginx或/usr/sbin/nginx start
停止：systemctl stop nginx
重启：/usr/sbin/nginx -s reload
分别修改两台机器的/usr/share/nginx/html/index.html以区分效果
加入启动项：
vi /etc/rc.local增加一行：/usr/sbin/nginx
若开启防火墙需要开放端口：
vi /etc/sysconfig/iptables
添加内容：-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
重启防火墙：service iptables restart或systemctl restartiptables.service
配置：（需要先将130和133tomcat配置好）
192.168.117.131增加文件：vi /etc/nginx/conf.d/131.conf
upstream my_server {
server 192.168.117.130:8080 weight=3;
server 192.168.117.133:8080 weight=3;
#keepalive 2000;
}
server {
listen80;
server_name192.168.117.131;
client_max_body_size 1024M;
location / {
proxy_pass http://my_server/;
proxy_set_header Host $host:$server_port;
}
}
192.168.117.132增加文件：vi /etc/nginx/conf.d/132.conf
upstream my_server {
server 192.168.117.133:8080 weight=3;
server 192.168.117.130:8080 weight=3;
#keepalive 2000;
}
server {
listen80;
server_name192.168.117.132;
client_max_body_size 1024M;
location / {
proxy_pass http://my_server/;
proxy_set_header Host $host:$server_port;
}
}
2、安装配置Keepalived
2.1、安装配置
安装：yuminstall keepalived
检查版本：keepalived –v
查看：whereis keepalived
配置：
（1）新建文件：vi /etc/keepalived/nginx_check.sh
#!/bin/bash
A=ps -C nginx –no-header |wc -lif [ $A -eq 0 ];then
/usr/sbin/nginx
sleep 2
if [ps -C nginx--no-header |wc -l-eq 0 ];then
killall keepalived
fi
fi
（2）编辑keepalived.conf：vi /etc/keepalived/keepalived.conf
192.168.117.131如下：
! Configuration Filefor keepalived
global_defs {
router_idnode-01
}
vrrp_script chk_nginx {
script"/etc/keepalived/nginx_check.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
stateMASTER
interfaceens33
virtual_router_id 146
mcast_src_ip192.168.117.131
priority100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.117.150
}
}
192.168.117.132如下：
! Configuration File for keepalived
global_defs {
router_idnode-02
}
vrrp_script chk_nginx {
script"/etc/keepalived/nginx_check.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
stateBACKUP
interfaceens33 #网卡
virtual_router_id 146
mcast_src_ip192.168.117.132
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.117.150
}
}
interfaceens33为网卡
3、安装配置memcached
3.1、安装配置
安装：yum -y install memcached
重启：service memcached restart
启动：service memcached start
开机启动：service memcached enable
状态：service memcached status
关闭：service memcached stop
查看状态：memcached-tool127.0.0.1:11211 stats
4、安装配置tomcat
进入目录：cd /home/wangyong
创建目录：mkdir test
上传：apache-tomcat-8.5.20.tar.gz到/home/wangyong/test/
解压：tar –zxvf apache-tomcat-8.5.20.tar.gz
重命名：mv apache-tomcat-8.5.20 tomcat-8.5.20
创建lib目录：mkdir memcachedlib
进入目录：cd /home/wangyong/memcachedlib下载以下依赖包
#下载memcached-session-manager jars to tomcat
wget http://repo1.maven.org/maven2/de/javakaffee/msm/memcached-session-manager/1.9.5/memcached-session-manager-1.9.5.jar
wget
http://repo1.maven.org/maven2/de/javakaffee/msm/memcached-session-manager-tc8/1.9.5/memcached-session-manager-tc8-1.9.5.jar
#使用memcached的时候要用到的jar文件
wget
http://repo1.maven.org/maven2/net/spy/spymemcached/2.11.1/spymemcached-2.11.1.jar
#使用javolution-serializer的时候用到的jar文件下载
wget
http://repo1.maven.org/maven2/de/javakaffee/msm/msm-javolution-serializer/1.9.5/msm-javolution-serializer-1.9.5.jar
wget http://www.java2s.com/Code/JarDownload/javolution/javolution-5.5.1.jar.zip
unzip
javolution-5.5.1.jar.zip
#下面是使用kryo-serializer的时候用到的jar文件下载
wget
http://repo1.maven.org/maven2/de/javakaffee/msm/msm-kryo-serializer/1.9.5/msm-kryo-serializer-1.9.5.jar
wget
http://repo1.maven.org/maven2/de/javakaffee/kryo-serializers/0.9/kryo-serializers-0.9.jar
#(相配合的kryo只能用3.+的版本。)
wget
http://repo1.maven.org/maven2/com/esotericsoftware/kryo/3.0.3/kryo-3.0.3.jar
wget
http://repo1.maven.org/maven2/com/esotericsoftware/minlog/1.3.0/minlog-1.3.0.jar
wget
http://repo1.maven.org/maven2/com/esotericsoftware/reflectasm/1.11.3/reflectasm-1.11.3.jar
wget http://repo1.maven.org/maven2/org/ow2/asm/asm/5.1/asm-5.1.jar
将所下载的包移动到tomcat的lib目录下
mv *.jar /home/wangyong/test/tomcat-8.5.20/lib/
配置tomcat的context.xml
cd /home/wangyong/test/tomcat-8.5.20/conf
vi context.xml
增加以下内容：
sticky="false"
memcachedNodes="n1:192.168.117.130:11211 n2:192.168.117.133:11211"
failoverNodes=""
requestUriIgnorePattern=".*\.(png|gif|jpg|css|js|ico)$"
sessionBackupAsync="false"
sessionBackupTimeout="500"
transcoderFactoryClass="de.javakaffee.web.msm.serializer.javolution.JavolutionTranscoderFactory"
/>
四、运行调试
首先要把memcached的服务启动，然后是nginx服务，最后启动tomcat所在的每个子节点的服务
五、参考文章
1、Keepalived+Nginx实现高可用Web负载均衡
http://www.jianshu.com/p/da26df4f7d60
2、nginx代理配置
http://www.cnblogs.com/fanzhidongyzby/p/5194895.html
3、nginx+tomcat7集群，负载均衡和session共享
http://blog.csdn.net/remote_roamer/article/details/51133790
