Linux下配置Nginx + Tomcat负载均衡

Nginx简介

Nginx ("engine x") 是一个高性能的 HTTP 和反向代理服务器，也是一个 IMAP/POP3/SMTP 代理服务器。 Nginx 是由 Igor Sysoev 为俄罗斯访问量第二的Rambler.ru 站点开发的，它已经在该站点运行超过四年多了。Igor 将源代码以类BSD许可证的形式发布。自Nginx 发布四年来，Nginx 已经因为它的稳定性、丰富的功能集、示例配置文件和低系统资源的消耗而闻名了。目前国内各大门户网站已经部署了Nginx，如新浪、网易、腾讯等；国内几个重要的视频分享网站也部署了Nginx，如六房间、酷6等。新近发现Nginx 技术在国内日趋火热，越来越多的网站开始部署Nginx。

JDK安装

[root@localhost export]# chmod 777 jdk-6u45-linux-x64.bin
[root@localhost export]# ./jdk-6u45-linux-x64.bin
[root@localhost export]# mv jdk-6u45 jdk
[root@localhost export]# vi /etc/profile
export JAVA_HOME=/usr/local/jdk1.7.0
export CLASSPATH=.:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar
export PATH=$JAVA_HOME/bin:$PATH
保存退出
:wq
使环境变量生效
#source /etc/profile
测试JDK
[root@localhost export]# java -version
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode)

TOMCAT的安装

[root@localhost tomcat]# tar -zxvf apache-tomcat-7.0.53.tar.gz
[root@localhost tomcat]# mv apache-tomcat-7.0.53 tomcat

#ev-tomcat
export TOMCAT_HOME=/export/servers/tomcat
export CATALINA_HOME=/export/servers/tomcat
export CATALINA_BASE=/export/servers/tomcat
保存退出
:wq
使环境变量生效
[root@localhost tomcat]# source /etc/profile

修改TOMCAT配置文件/export/servers/tomcat/conf/server.xml

将以下内容
    <Host name="localhost" appBase="webapps"
    .../>
修改为
    <Host name="localhost" appBase="/export/data/web"
    .../>

启动tomcat
[root@localhost bin]# sh startup.sh
Using CATALINA_BASE:   /export/servers/tomcat
Using CATALINA_HOME:   /export/servers/tomcat
Using CATALINA_TMPDIR: /export/servers/tomcat/temp
Using JRE_HOME:        /export/jdk
Using CLASSPATH:       /export/servers/tomcat/bin/bootstrap.jar:/export/servers/tomcat/bin/tomcat-juli.jar
Tomcat started.
关闭tomcat
[root@localhost bin]# sh shutdown.sh
Using CATALINA_BASE:   /export/servers/tomcat
Using CATALINA_HOME:   /export/servers/tomcat
Using CATALINA_TMPDIR: /export/servers/tomcat/temp
Using JRE_HOME:        /export/jdk
Using CLASSPATH:       /export/servers/tomcat/bin/bootstrap.jar:/export/servers/tomcat/bin/tomcat-juli.jar

同一linux系统下安装多个TOMCAT

将TOMCAT安装在/export/servers/tomcat_2
设置环境变量
#vi /etc/profile
export TOMCAT_2_HOME=/export/servers/tomcat_2
export CATALINA_2_HOME=/export/servers/tomcat_2
export CATALINA_2_BASE=/export/servers/tomcat_2
在PATH后面添加：$CATALINA_2_HOME/lib
保存退出
:wq
使环境变量生效
#source /etc/profile

修改TOMCAT配置文件/export/servers/tomcat_2/conf/server.xml

将以下内容
    <Server port="8005" shutdown="SHUTDOWN">...
    <Connector port="8080" protocol="HTTP/1.1" ...
    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />
    <Host name="localhost" appBase="webapps"
    .../>
修改为
    <Server port="9005" shutdown="SHUTDOWN">...
    <Connector port="9090" protocol="HTTP/1.1" ...
    <Connector port="9009" protocol="AJP/1.3" redirectPort="8443" />
    <Host name="localhost" appBase="/usr/local/www/web"
    .../>

修改TOMCAT配置启动文件/export/servers/tomcat_2/bin/startup.sh

在exec上添加以下内容
export JAVA_HOME=/usr/java/jdk1.7.0
export CLASSPATH=$JAVA_HOME/lib
export PATH=$JAVA_HOME/bin
export CATALINA_HOME=$CATALINA_2_HOME
export CATALINA_BASE=$CATALINA_2_BASE

修改TOMCAT配置启动文件/export/servers/tomcat_2/bin/shutdown.sh

在exec上添加以下内容
export JAVA_HOME=/usr/java/jdk1.7.0
export CLASSPATH=$JAVA_HOME/lib
export PATH=$JAVA_HOME/bin
export CATALINA_HOME=$CATALINA_2_HOME
export CATALINA_BASE=$CATALINA_2_BASE

启动TOMCAT
/export/servers/tomcat_2/bin/startup.sh
关闭TOMCAT
/export/servers/tomcat_2/bin/shutdown.sh

NGINX的安装

检查安装nginx的依赖性，nginx的模块需要第三方的支持，检查是否安装下列库：

[root@localhost bin]# yum install zlib zlib-devel openssl openssl-devel pcre pcre-devel gcc

添加用户和组

[root@localhost bin]# groupadd nginx
[root@localhost bin]# useradd -g nginx nginx

安装nginx

[root@localhost servers]#tar -zxvf nginx-1.7.7.tar.gz

[root@localhost servers]#mv nginx-1.7.7 ngnix

[root@localhost servers]#cd ngnix

[root@localhost ngnix]#./configure --user=nginx --group=nginx --prefix=/export/servers/nginx

[root@localhost ngnix]#make

[root@localhost ngnix]#make install

修改/export/servers/nginx/conf/nginx.conf

user nginx nginx;

worker_processes 2;

error_log /usr/local/nginx/logs/nginx_error.log crit;

pid /usr/local/nginx/logs/nginx.pid;

#Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_nofile 65535;

events
{
use epoll;
worker_connections 65535;

}

http
{
include mime.types;
default_type application/octet-stream;

charset utf-8;

server_names_hash_bucket_size 128;
client_header_buffer_size 32k;
large_client_header_buffers 4 32k;
client_max_body_size 300m;

sendfile on;
tcp_nopush     on;

keepalive_timeout 60;

tcp_nodelay on;

client_body_buffer_size 512k;
proxy_connect_timeout    5;
proxy_read_timeout       60;
proxy_send_timeout       5;
proxy_buffer_size        16k;
proxy_buffers            4 64k;
proxy_busy_buffers_size 128k;
proxy_temp_file_write_size 128k;

gzip on;
gzip_min_length 1k;
gzip_buffers 4 16k;
gzip_http_version 1.1;
gzip_comp_level 2;
gzip_types text/plain application/x-javascript text/css application/xml;
gzip_vary on;

#注：proxy_temp_path和proxy_cache_path指定的路径必须在同一分区
proxy_temp_path   /export/home/www/proxy_temp_dir;
#设置Web缓存区名称为cache_one，内存缓存空间大小为200MB，1天没有被访问的内容自动清除，硬盘缓存空间大小为30GB。
proxy_cache_path /export/home/www/proxy_cache_dir levels=1:2   keys_zone=cache_one:200m inactive=1d max_size=30g;

upstream backend_server {
    server   127.0.0.1:8080 weight=1 max_fails=2 fail_timeout=30s;
    server   127.0.0.1:9090 weight=1 max_fails=2 fail_timeout=30s;
    ip_hash;
}

server
{
    listen       80;
    server_name localhost;
    index index.html index.htm;
    root /export/home/www/web/ROOT;

    location /
    {
         #如果后端的服务器返回502、504、执行超时等错误，自动将请求转发到upstream负载均衡池中的另一台服务器，实现故障转移。
         proxy_next_upstream http_502 http_504 error timeout invalid_header;
         proxy_cache cache_one;
         #对不同的HTTP状态码设置不同的缓存时间
         proxy_cache_valid 200 304 12h;
         #以域名、URI、参数组合成Web缓存的Key值，Nginx根据Key值哈希，存储缓存内容到二级缓存目录内
         proxy_cache_key $host$uri$is_args$args;
         proxy_set_header Host $host;
         proxy_set_header X-Forwarded-For $remote_addr;
         proxy_pass http://backend_server;
         expires      1d;
    }

    #用于清除缓存，假设一个URL为http://192.168.168.106/test.txt，通过访问http://192.168.168.106/purge/test.txt就可以清除该URL的缓存。
    location ~ /purge(/.*)
    {
     #设置只允许指定的IP或IP段才可以清除URL缓存。
     allow            127.0.0.1;
     allow            192.168.0.0/16;
     deny            all;
     proxy_cache_purge    cache_one   $host$1$is_args$args;
    }

    #扩展名以.php、.jsp、.cgi结尾的动态应用程序不缓存。
    location ~ .*.(php|jsp|cgi)?$
    {

         proxy_set_header Host $host;
         proxy_set_header X-Forwarded-For $remote_addr;
         proxy_pass http://backend_server;

}

access_log off;
}
}

创建缓存文件夹
[root@localhost ngnix]#mkdir /export/home/www/proxy_temp_dir
[root@localhost ngnix]#mkdir /export/home/www/proxy_cache_dir

启动NGINX
[root@localhost ngnix]#./export/servers/nginx/sbin/nginx
关闭NGINX
[root@localhost ngnix]#./export/servers/nginx/sbin/nginx -s stop
重启NGINX
[root@localhost ngnix]#./export/servers/nginx/sbin/nginx -s relo