keepalived+nginx安装配置

软件版本号：
pcre8.36 ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.36.tar.gz  
keepalived1.2.19
http://www.keepalived.org/software/keepalived-1.2.19.tar.gz
nginx1.8.0
http://nginx.org/download/nginx-1.8.0.tar.gz<pre name="code" class="html"><pre name="code" class="html">安装步骤
安装pcre
tar -zxvf pcre-8.36.tar.gz
cd pcre-8.36
./configure --prefix=/usr/local/pcre
make && make install
安装keepalived
tar -zxvf keepalived-1.2.19.tar.gz
cd keepalived-1.2.19
./configure --prefix=/usr/local/keepalived
make && make install
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
mkdir –pv /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
ln -s /usr/local/keepalived/sbin/keepalived /sbin/
chkconfig keepalived on
安装nginx
tar -zxvf nginx-1.8.0.tar.gz
cd nginx-1.8.0
./configure --prefix=/usr/local/nginx --with-pcre=/usr/local/pcre/
make && make install

<strong><span style="font-size:18px;">启动和停止</span></strong>
Nginx:
启动：进入到安装之后${nginx}的sbin文件夹。运行./nginx
停止：./nginx –s stop
检查是否成功安装：进入到安装之后${nginx}的sbin文件夹，运行./nginx -t
 
Keepalived
启动：service keepalived start
停止：service keepalived stop

<strong><span style="font-size:18px;">配置</span></strong>
配置Keepalived
主备keepalived的配置大致同样，不同之处在于state和priority。
例如以下所看到的：
! Configuration File for keepalived
#配置报警邮件
global_defs {
   notification_email {
     acassen@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
#配置keepalived服务器实例
vrrp_instance VI_1 {#VI_1为名称
    state MASTER  #MASTER为主服务器。BACKUP为备用服务器
    interface p2p1  #p2p1为网卡标志
    virtual_router_id 51 #51为默认值
    priority 100  #主服务器的优先级要大于备服务器
    advert_int 1 #1为默认值
    authentication {#认证，採用默认值就可以
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {#对外提供的虚拟IP，不能与现有IP冲突
        200.31.157.243
    }
}

配置Nginx
Nginx的基本配置例如以下所看到的：
#user  nobody; #username称
worker_processes  auto; #处理进程个数，一般为自己主动分配
error_log   logs/error.log; #错误日志记录位置
#error_log  logs/error.log  notice; #notice/info等为记录错误的级别
#error_log  logs/error.log  info;
pid        logs/nginx.pid; #进程记录文件

events {
    worker_connections  5120; #可处理的连接数，最大处理能力为processes×connections
}

http {
    include       mime.types;
default_type  application/octet-stream;
#配置日志格式（main为自己定义格式名称）
    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; #日志文件位置
    keepalive_timeout  65; #连接超时时间
    proxy_connect_timeout 10; #后台服务器响应超时时间

    #配置反向代理
    upstream tomcat{ #tomcat为名称
	  server 200.31.157.116:8090 weight=1; #后台服务器的地址以及port号。weight为权重 
	  server 200.31.157.117:8090 weight=1;
    }    

    #配置负载均衡，Server为nginx服务器
    upstream nginx{
       server 200.31.157.116:8084 weight=1;
	  server 200.31.157.117:8084 weight=1;
}

#配置处理请求Server
    server{
        listen       8084; #监听的port号
        server_name  200.31.157.243; #自己定义服务名称，不能与其他Server有冲突
        #charset koi8-r;  #定义字符集
        #access_log  logs/host.access.log  main; #定义日志名称与日志格式(main)

        #设定訪问处理规则。假设路径以/cwap开头，则通过下面规则进行处理
        location /cwap {
	      proxy_pass http://tomcat; #反向代理到tomcat服务器该处的tomcat为upstream名称
	      proxy_redirect off;
	      proxy_set_header Host $host; #下面是读取訪问IP
	      proxy_set_header X-Real-IP $remote_addr;
	      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        location / {
           root   html; #根文件夹
           index  index.html index.htm;
        }
        #error_page  404              /404.html; #配置错误页面

        # redirect server error pages to the static page /50x.html
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
    server{
        listen       80;
        server_name  localhost;
        access_log  logs/access.log  main;
        location /cwap {
	      proxy_pass http://nginx;
	      proxy_redirect off;
	      proxy_set_header Host $host;
	      proxy_set_header X-Real-IP $remote_addr;
	      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        }

        location / {
           root   html;
           index  index.html index.htm;
	      #expires 1d; #页面缓存时间
        }
        error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}

<strong><span style="font-size:18px;">负载均衡</span></strong>
nginx 的 upstream眼下支持 4 种方式的分配
轮询（默认）
每一个请求按时间顺序逐一分配到不同的后端服务器，假设后端服务器down掉。能自己主动剔除。

weight
定轮询几率。weight和訪问比率成正比，用于后端服务器性能不均的情况。
ip_hash
每一个请求按訪问ip的hash结果分配，这样每一个訪客固定訪问一个后端服务器。能够解决session的问题。
fair（第三方）
按后端服务器的响应时间来分配请求。响应时间短的优先分配。

在http中upstream配置中，clouder是起的负载均衡服务器或者反向代理的名称。

upstream clouder {
	#ip_hash;
	#least_conn;
	server 200.31.157.116:8090; 
	server 200.31.157.116:9090 down; #表示当前server临时不參与负载
	server 200.31.157.117:8090 weight=2; #默觉得1,weight越大,负载的权重越大
        #其他全部非backup机器down或忙时。请求backup机器。所以这台机器压力会最轻
	server 200.31.157.117:9090 backup;		
<span style="white-space:pre">	</span>server 200.31.157.117:8084 fail_timeout=10s; #失败后的暂停时间
<span style="white-space:pre">	</span>#最大失败次数为2，失败后暂停时间为10
	server 200.31.157.117:8083 max_fails=2  fail_timeout=10s; 
}