Nginx+Keepalived+Tomcat+Memcached 实现双VIP负载均衡及Session会话保持

Nginx+Keepalived+Tomcat+Memcached 实现双VIP负载均衡及Session会话保持

IP 信息列表：
名称 IP 软件

VIP1 192.168.200.254
VIP2 192.168.200.253
nginx-1 192.168.200.101 nginx keepalived
nginx-2 192.168.200.102 nginx keepalived
tomcat-1 192.168.200.103 tomcat memcached
tomcat-2 192.168.200.104 tomcat memcached
所有机器关闭防火墙及Selinux：
[root@localhost ~]# service iptables stop
[root@localhost ~]# setenforce 0
安装配置JDK和Tomcat服务器：

安装配置JDK：
将jdk-7u65-linux-x64.tar.gz解压
[root@tomcat-1 ~]# rm -rf /usr/bin/java
[root@tomcat-1 ~]# tar xf jdk-7u65-linux-x64.tar.gz
解压后会生成jdk1.7.0_65文件夹，将文件夹移动到/usr/local下并重命名为java
[root@tomcat-1 ~]# mv jdk1.7.0_65/ /usr/local/java
在/etc/profile.d/ 下建立java.sh脚本
[root@tomcat-1 ~]# vim /etc/profile #末尾出追加
export JAVA_HOME=/usr/local/java #设置java根目录
export PATH=$PATH:$JAVA_HOME/bin #在PATH环境变量中添加java跟目录的bin子目录
将java.sh 脚本导入到环境变量，使其生效
[root@tomcat-1 ~]# source /etc/profile
运行 java -version 或者 javac -version 命令查看java版本
[root@tomcat-1 ~]# java -version
java version “1.7.0_65”
OpenJDK Runtime Environment (rhel-2.5.1.2.el6_5-x86_64 u65-b17)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)
[root@tomcat-1 ~]# javac -version
javac 1.7.0_65
安装配置Tomcat：
解压软件包
[root@tomcat-1 ~]# tar xf apache-tomcat-7.0.54.tar.gz
解压后生成apache-tomcat-7.0.54文件夹，将该文件夹移动到/usr/local下，并改名为tomcat7
[root@tomcat-1 ~]# mv apache-tomcat-7.0.54 /usr/local/tomcat7
启动Tomcat
[root@tomcat-1 ~]# /usr/local/tomcat7/bin/startup.sh
Using CATALINA_BASE: /usr/local/tomcat7
Using CATALINA_HOME: /usr/local/tomcat7
Using CATALINA_TMPDIR: /usr/local/tomcat7/temp
Using JRE_HOME: /usr/local/java
Using CLASSPATH: /usr/local/tomcat7/bin/bootstrap.jar:/usr/local/tomcat7/bin/tomcat-juli.jar
Tomcat started.
Tomcat 默认运行在8080端口
[root@tomcat-1 ~]# netstat -anpt |grep :8080
tcp 0 0 :::8080 ::? LISTE
N 55349/java
关闭Tomcat
[root@tomcat-1 ~]# /usr/local/tomcat7/bin/shutdown.sh
浏览器访问测试 http://192.168.200.103:8080
建立java的web站点：
首先在跟目录下建立一个webapp目录，用于存放网站文件
[root@tomcat-1 ~]# mkdir /webapp
在webapp1目录下建立一个index.jsp的测试页面
[root@tomcat-1 ~]# vim /webapp/index.jsp
Server Info:
SessionID:<%=session.getId()%>


SessionIP:<%=request.getServerName()%>


SessionPort:<%=request.getServerPort()%>


<%
out.println(“server one”);
%>

修改Tomcat的server.xml文件
定义一个虚拟主机，并将网站文件路径指向已经建立的/webapp，在host段增加context段
[root@tomcat-1 ~]# cp /usr/local/tomcat7/conf/server.xml{,.bak}
[root@tomcat-1 ~]# vim /usr/local/tomcat7/conf/server.xml
124 <Host name=“localhost” appBase=“webapps”
125 unpackWARs=“true” autoDeploy=“true”>
126
127
docBase="/webapp" #web应用的文档基准目录
path="" #设置默认"类"
reloadable=“flase” #设置监视"类"是否变化
关闭tomcat，在重新启动
[root@tomcat-1 ~]# /usr/local/tomcat7/bin/shutdown.sh
Using CATALINA_BASE: /usr/local/tomcat7
Using CATALINA_HOME: /usr/local/tomcat7
Using CATALINA_TMPDIR: /usr/local/tomcat7/temp
Using JRE_HOME: /usr/local/java
Using CLASSPATH: /usr/local/tomcat7/bin/bootstrap.jar:/usr/local/tomcat7/bin/tomcat-juli.jar
[root@tomcat-1 ~]# /usr/local/tomcat7/bin/startup.sh
Using CATALINA_BASE: /usr/local/tomcat7
Using CATALINA_HOME: /usr/local/tomcat7
Using CATALINA_TMPDIR: /usr/local/tomcat7/temp
Using JRE_HOME: /usr/local/java
Using CLASSPATH: /usr/local/tomcat7/bin/bootstrap.jar:/usr/local/tomcat7/bin/tomcat-juli.jar
Tomcat started.
浏览器访问测试 http://192.168.200.103:8080

Tomcat 2 配置方法基本与Tomcat 1 相同
安装JDK，配置Java环境，版本与Tomcat 1 保持一致
安装Tomcat，版本与Tomcat 1 保持一致
[root@tomcat-2 ~]# vim /webapp/index.jsp
Server Info:
SessionID:<%=session.getId()%>


SessionIP:<%=request.getServerName()%>


SessionPort:<%=request.getServerPort()%>


<%
out.println(“server two”);
%>
[root@tomcat-2 ~]# cp /usr/local/tomcat7/conf/server.xml{,.bak}
[root@tomcat-2 ~]# vim /usr/local/tomcat7/conf/server.xml
124 <Host name=“localhost” appBase=“webapps”
125 unpackWARs=“true” autoDeploy=“true”>
126
127
[root@tomcat-2 ~]# /usr/local/tomcat7/bin/shutdown.sh
[root@tomcat-2 ~]# /usr/local/tomcat7/bin/startup.sh
浏览器访问测试 http://192.168.200.104:8080

Tomcat 配置相关说明
/usr/local/tomcat7 #主目录
bin #存放windows或linux平台上启动或关闭的Tomcat的脚本文件
conf #存放Tomcat的各种全局配置文件，其中最主要的是server.xml和web.xml
lib #存放Tomcat运行需要的库文件(JARS)
logs #存放Tomcat执行时的LOG文件
webapps #Tomcat的主要Web发布目录（包括应用程序事例）
work #存放jsp编译后产生的class文件
[root@tomcat-1 ~]# ls /usr/local/tomcat7/conf/
catalina.policy #权限控制配置文件
catalina.properties #Tomcat属性配置文件
context.xml #上下文配置文件（selinux）
logging.properties #日志log相关配置文件
server.xml #主配置文件
tomcat-users.xml #manager-gui管理用户配置文件（Tomcat安装后生成的管理界面，该文件可开启访问）
web.xml #Tomcat的servlet，servlet-mapping，filter，MIME等相关配置
server.xml 主要配置文件，可修改启动端口，设置网站根目录，虚拟主机，开启https等功能。
server.xml的结构构成

内的内容是注视信息
Server
Server元素代表了整个Catalina的Servlet容器
Service
Service是这样一个集合；它由一个或多个Connector组成，以及一个Engine，负责处理所有Connector所获得的客户请求。
Connector
一个Connector在某个指定端口上侦听客户请求，并将获得的请求交给Engine来处理，从Engine处获得回应并返回客户。
TomcatEngine有两个典型的Connector，一个直接侦听来自browser的http请求，一个侦听来自其他webserver的请求
Coyote Http/1.1 Connector在端口8009处侦听来自其他wenserver（Apache）的servlet/jsp代理请求。
Engine
Engine下可以配置多个虚拟主机Virtual Host,每个虚拟主机都有一个域名
当Engine获得一个请求时，它把该请求匹配到某一个Host上，然后把该请求交给该Host来处理，
Engine有一个默认的虚拟主机，当请求无法匹配到任何一个Host上的时候，将交给该默认Host来处理
Host
代表一个Virtual Host，虚拟主机，每个虚拟主机和某个网络域名Domain Name相匹配
每个虚拟主机下都可以部署（deploy）一个或者多个Web app，每个web app 对应一个Context，有一个Context path。
当Host获得一个请求时，将把该请求匹配到某个Context上，然后把该请求交给该Context来处理，匹配的方法是最长匹配，所以一个path==“”的Context将成为该Host的默认Context匹配。
Context
一个Context对应一个 Web application，一个 Web application由一个或者多个Servlet组成。

nginx-1服务器配置：
[root@nginx-1 ~]# yum -y install pcre-devel zlib-devel openssl-devel
[root@nginx-1 ~]# useradd -M -s /sbin/nologin nginx
[root@nginx-1 ~]# tar xf nginx-1.6.2.tar.gz
[root@nginx-1 ~]# cd nginx-1.6.2
[root@nginx-1 nginx-1.6.2]# ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx --with-file-aio --with-http_stub_status_module --with-http_ssl_module --with-http_flv_module --with-http_gzip_static_module && make && make install
–prefix=/usr/local/nginx #指定安装目录
–user=nginx --group=nginx #指定运行的用户和组
–with-file-aio #启用文件修改支持
–with-http_stub_status_module #启用状态统计
–with-http_ssl_module #启用ssl模块
–with-http_flv_module #启用flv模块，提供寻求内存使用基于时间的偏移量文件
–with-http_gzip_static_module #启用gzip静态压缩
配置nginx.conf
[root@nginx-1 nginx-1.6.2]# cp /usr/local/nginx/conf/nginx.conf{,.bak}
[root@nginx-1 nginx-1.6.2]# vim /usr/local/nginx/conf/nginx.conf

user nginx;
worker_processes 1;
error_log logs/error.log;
pid logs/nginx.pid;
events {
use epoll;
worker_connections 10240;
}
http {
include mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remot{e}_{u}ser[$time_local] “KaTeX parse error: Double superscript at position 34: … '̲status $bod{y}_{b}yte{s}_{s}ent"$http_referer” ’
‘“$htt{p}_{u}se{r}_{a}gent""$http_x_forwarded_for”’;
access_log logs/access.log main;
sendfile on;
keepalive_timeout 65;
upstream tomcat_server {
server 192.168.200.103:8080 weight=1;
server 192.168.200.104:8080 weight=1;
}
server {
listen 80;
server_name localhost;
location / {
root html;
index index.html index.htm;
proxy_pass http://tomcat_server;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}

[root@nginx-1 nginx-1.6.2]# /usr/local/nginx/sbin/nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful
[root@nginx-1 nginx-1.6.2]# /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf
[root@nginx-1 nginx-1.6.2]# netstat -anpt |grep :80
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 7184/nginx
[root@nginx-1 nginx-1.6.2]# ps aux |grep nginx
root 7184 0.0 0.2 45000 1052 ? Ss 01:18 0:00 nginx: master process /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf
www 7185 0.0 1.1 49256 5452 ? S 01:18 0:00 nginx: worker process
root 7193 0.0 0.1 103256 848 pts/1 S+ 01:18 0:00 grep nginx
客户端测试：
打开浏览器访问: http://192.168.200.101 #不断刷新可看到由于权重相同，页面会反复切换
nginx-2服务器配置：
配置方式与服务器nginx-1一致
客户端测试：
打开浏览器访问: http://192.168.200.102 #不断刷新可看到由于权重相同，页面会反复切换

工作原理：两台Nginx通过Keepalived生成二个实例，二台Nginx的VIP互为备份，任何一台Nginx机器如果发生硬件损坏，Keepalived会自动将它的VIP地址切换到另一台机器，不影响客户端的访问。
在nginx1/2上编译安装keepalived服务：
[root@nginx-1 ~]# yum -y install kernel-devel openssl-devel
[root@nginx-1 ~]# tar xf keepalived-1.2.13.tar.gz
[root@nginx-1 ~]# cd keepalived-1.2.13
[root@nginx-1 keepalived-1.2.13]# ./configure --prefix=/ --with-kernel-dir=/usr/src/kernels/2.6.32-504.el6.x86_64/ && make && make install
[root@nginx-1 ~]# chkconfig --add keepalived
[root@nginx-1 ~]# chkconfig keepalived on
[root@nginx-1 ~]# chkconfig --list keepalived
3、修改keepalived配置文件
[root@nginx-1 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[e-mail]
}
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 50
advert_int 1
authentication {
auth_type PASS
auth_pass 123
}
virtual_ipaddress {
192.168.200.254
}
}
vrrp_instance VI_2 {
state MASTER
interface eth0
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123
}
virtual_ipaddress {
192.168.200.253
}
}

[root@nginx-2 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[e-mail]
}
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 123
}
virtual_ipaddress {
192.168.200.254
}
}
vrrp_instance VI_2 {
state BACKUP
interface eth0
virtual_router_id 52
priority 50
advert_int 1
authentication {
auth_type PASS
auth_pass 123
}
virtual_ipaddress {
192.168.200.253
}
}
[root@nginx-1 ~]# service keepalived start
[root@nginx-1 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:2d:3d:97 brd ff:ff:ff:ff:ff:ff
inet 192.168.200.202/24 brd 192.168.200.255 scope global eth0
inet 192.168.200.254/32 scope global eth0
inet6 fe80::20c:29ff:fe2d:3d97/64 scope link
valid_lft forever preferred_lft forever
[root@nginx-2 ~]# service keepalived start
[root@nginx-2 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:6f:7d:87 brd ff:ff:ff:ff:ff:ff
inet 192.168.200.102/24 brd 192.168.200.255 scope global eth0
inet 192.168.200.253/32 scope global eth0
inet6 fe80::20c:29ff:fe6f:7d87/64 scope link
valid_lft forever preferred_lft forever

客户端测试：
打开浏览器访问: http://192.168.200.253 #不断刷新可看到由于权重相同，页面会反复切换
客户端测试：
打开浏览器访问: http://192.168.200.254 #不断刷新可看到由于权重相同，页面会反复切换

nginx-1/2 二台机器都执行监控Nginx进程的脚本
[root@nginx-1 ~]# cat nginx_pidcheck
#!/bin/bash
while :
do
nginxpid=ps -C nginx --no-header | wc -l
if [ $nginxpid-eq0]then/usr/local/nginx/sbin/nginxkeeppid=$(ps -C keepalived --no-header | wc -l)
if [ $keeppid -eq 0 ]
then
/etc/init.d/keepalived start
fi
sleep 5
nginxpid=ps -C nginx --no-header | wc -l
if [ $nginxpid -eq 0 ]
then
/etc/init.d/keepalived stop
fi
fi
sleep 5
done
[root@nginx-1 ~]# sh nginx_pidcheck &
[root@nginx-1 ~]# vim /etc/rc.local
sh nginx_pidcheck &
这是执行无限循环的脚本，两台Nginx机器上都有执行此脚本，每隔5秒执行一次，用ps -C是命令来收集nginx的PID值到底是否为0，如果是0的话，即Nginx已经进程死掉，尝试启动nginx进程；如果继续为0，即Nginx启动失败，则关闭本机的Keeplaived服务，VIP地址则会由备机接管，当然了，整个网站就会全部由备机的Nginx来提供服务了，这样保证Nginx服务的高可用。
脚本测试：
[root@nginx-1 ~]# netstat -anpt |grep nginx
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 4321/nginx
[root@nginx-1 ~]# killall -s QUIT nginx
[root@nginx-1 ~]# netstat -anpt |grep nginx
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 59418/nginx
VIP转移测试：
[root@nginx-1 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:2d:3d:97 brd ff:ff:ff:ff:ff:ff
inet 192.168.200.101/24 brd 192.168.200.255 scope global eth0
inet 192.168.200.254/32 scope global eth0
inet6 fe80::20c:29ff:fe2d:3d97/64 scope link
valid_lft forever preferred_lft forever

[root@nginx-2 ~]# service keepalived stop
停止 keepalived： [确定]
[root@nginx-1 ~]# ip addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:2d:3d:97 brd ff:ff:ff:ff:ff:ff
inet 192.168.200.101/24 brd 192.168.200.255 scope global eth0
inet 192.168.200.254/32 scope global eth0
inet 192.168.200.253/32 scope global eth0
inet6 fe80::20c:29ff:fe2d:3d97/64 scope link
valid_lft forever preferred_lft forever
客户端测试：
打开浏览器访问: http://192.168.200.253 #不断刷新可看到由于权重相同，页面会反复切换
客户端测试：
打开浏览器访问: http://192.168.200.254 #不断刷新可看到由于权重相同，页面会反复切换

[root@tomcat-1 ~]# yum -y install gcc openssl-devel pcre-devel zlib-devel
[root@tomcat-1 ~]# tar xf libevent-2.0.15-stable.tar.gz
[root@tomcat-1 ~]# cd libevent-2.0.15-stable
[root@tomcat-1 libevent-2.0.15-stable]# ./configure --prefix=/usr/local/libevent && make && make install
[root@tomcat-1 ~]# tar xf memcached-1.4.5.tar.gz
[root@tomcat-1 ~]# cd memcached-1.4.5
[root@tomcat-1 memcached-1.4.5]# ./configure --prefix=/usr/local/memcached --with-libevent=/usr/local/libevent/ && make && make install
[root@tomcat-1 memcached-1.4.5]# ldconfig -v |grep libevent
libevent_pthreads-2.0.so.5 -> libevent_pthreads.so
libevent-2.0.so.5 -> libevent.so
libevent_extra-2.0.so.5 -> libevent_extra.so
libevent_core-2.0.so.5 -> libevent_core.so
libevent_openssl-2.0.so.5 -> libevent_openssl.so
libevent_extra-1.4.so.2 -> libevent_extra-1.4.so.2.1.3
libevent_core-1.4.so.2 -> libevent_core-1.4.so.2.1.3
libevent-1.4.so.2 -> libevent-1.4.so.2.1.3
[root@tomcat-1 memcached-1.4.5]# /usr/local/memcached/bin/memcached -u root -m 512M -n 10 -f 2 -d -vvv -c 512
/usr/local/memcached/bin/memcached: error while loading shared libraries: libevent-2.0.so.5: cannot open shared object file: No such file or directory
[root@localhost memcached-1.4.5]# vim /etc/ld.so.conf
include ld.so.conf.d/*.conf
/usr/local/libevent/lib/
[root@localhost memcached-1.4.5]# ldconfig
[root@localhost memcached-1.4.5]# /usr/local/memcached/bin/memcached -u root -m 512M -n 10 -f 2 -d -vvv -c 512
选项：
-h #查看帮助信息
-p #指定memcached监听的端口号默认11211
-l #memcached服务器的ip地址
-u #memcached程序运行时使用的用户身份必须是root用户
-m #指定使用本机的多少物理内存存数据默认64M
-c #memcached服务的最大链接数
-vvv #显示详细信息
-n #chunk size 的最小空间是多少单位字节
-f #chunk size大小增长的倍数默认 1.25倍
-d #在后台启动

[root@tomcat-1 ~]# netstat -antp| grep :11211 #（检测memecached是否存活，memcacehd 端口为11211）
tcp 0 0 0.0.0.0:11211 0.0.0.0:* LISTEN 71559/memcached
tcp 0 0 :::11211 ::? LISTEN 71559/memcached
测试memcached 能否存取数据
[root@tomcat-1 ~]# yum -y install telnet
[root@localhost ~]# telnet 192.168.200.103 11211
set username 0 0 8
zhangsan
STORED
get username
VALUE username 0 8
zhangsan
END
quit
Connection closed by foreign host.
最后执行让Tomcat-1 Tomcat-2 通过（msm）连接到Memcached
将session包中的“.jar复制到/usr/local/tomcat7/lib/ 下面
[root@tomcat-1 ~]# cp session/ /usr/local/tomcat7/lib/
编辑tomcat 配置文件连接指定的 memcached服务器
tomcat-1 和 tomcat-2 配置文件一模一样，都按照一下样例写
[root@tomcat-1 ~]# vim /usr/local/tomcat7/conf/context.xml



[root@tomcat-2 ~]# vim /usr/local/tomcat7/conf/context.xml



[root@tomcat-1 ~]# /usr/local/tomcat7/bin/shutdown.sh
[root@tomcat-1 ~]# /usr/local/tomcat7/bin/startup.sh
如果成功，tomcat与Memcached 端口会连在一起，前后有变化
Tomcat-1与Tomcat-2如下图
[root@tomcat-1 ~]# netstat -antp|grep java
tcp 0 0 ::ffff:127.0.0.1:8005 ::? LISTEN 62496/java
tcp 0 0 :::8009 ::? LISTEN 62496/java
tcp 0 0 :::8080 ::? LISTEN 62496/java
tcp 0 0 ::ffff:192.168.200.10:28232 ::ffff:192.168.200.10:11211 ESTABLISHED 62496/java
tcp 0 0 ::ffff:192.168.200.10:28231 ::ffff:192.168.200.10:11211 ESTABLISHED 62496/java
tcp 0 0 ::ffff:192.168.200.10:28230 ::ffff:192.168.200.10:11211 ESTABLISHED 62496/java
tcp 0 0 ::ffff:192.168.200.10:28228 ::ffff:192.168.200.10:11211 ESTABLISHED 62496/java
tcp 0 0 ::ffff:192.168.200.10:28229 ::ffff:192.168.200.10:11211 ESTABLISHED 62496/java
[root@tomcat-1 ~]# netstat -antp|grep memcached
tcp 0 0 0.0.0.0:11211 0.0.0.0:* LISTEN 62402/memcached
tcp 0 0 192.168.200.103:11211 192.168.200.103:28230 ESTABLISHED 62402/memcached
tcp 45 0 192.168.200.103:11211 192.168.200.103:28228 ESTABLISHED 62402/memcached
tcp 0 0 192.168.200.103:11211 192.168.200.103:28232 ESTABLISHED 62402/memcached
tcp 0 0 192.168.200.103:11211 192.168.200.103:28229 ESTABLISHED 62402/memcached
tcp 0 0 192.168.200.103:11211 192.168.200.103:28231 ESTABLISHED 62402/memcached
tcp 0 0 :::11211 ::? LISTEN 62402/memcached****