nginx+keepalived+tomcat实现的高可用

　　　　cd nginx-1.8.1 

　　　　./configure --prefix=/home/hadoop/apps/nginx 

　　　　make

　　　　make install

　　　　安装完成之后，检查nginx的配置文件是否正确

　　　　cd /home/hadoop/apps/nginx/sbin/

　　　　./nginx -t

user nobody;

worker_processes 2;

events{
    worker_connections 1024;
}

http{
    #设置默认类型为二进制流
    default_type    application/octet-stream;

    server_names_hash_bucket_size   128;
    #指定来自client请求头的headerbuffer大小。设置为32KB
    client_header_buffer_size   32k;
    #指定client请求中较大的消息头的缓存最大数量和大小，这里是4个32KB
    large_client_header_buffers 4 32k;
    #上传文件大小
    client_max_body_size 356m;
    #nginx的HttpLog模块指定，指定nginx日志的输出格式，输出格式为access
    log_format access ‘$remote_addr - $remote_user [$time_local] "$request" ‘
    ‘$status $body_bytes_sent "$http_referer" ‘
    ‘"$http_user_agent" "$http_x_forwarded_for"‘;
    #access日志存在未知
    access_log  /home/hadoop/apps/nginx/logs/access.log    access;
    #开启高效模式文件传输模式，将tcp_nopush和tcp_nodelay两个指另设置为on，用于防止网络堵塞。

    sendfile    on;
    tcp_nopush  on;
    tcp_nodelay on;
    #设置client连接保持活动的超时时间
    keepalive_timeout   65;
    server_tokens   off;
    #client请求主体读取缓存
    client_body_buffer_size 512k;
    proxy_connect_timeout   5;
    proxy_send_timeout      60;
    proxy_read_timeout      5;
    proxy_buffer_size       16k;
    proxy_buffers           4 64k;
    proxy_busy_buffers_size 128k;
    proxy_temp_file_write_size 128k;

    #fastcgi_connect_timeout 300;
    #fastcgi_send_timeout   300;
    #fastcgi_read_timeout   300;
    #fastcgi_buffer_timeout 300;
    #fastcgi_buffers 4 64k;
    #fastcgi_busy_buffers_size 128k;
    #fastcgi_temp_file_write_size 128k;

    #开启gzip
    gzip    on;
    #同意压缩的最小字节数
    gzip_min_length 1k;
    #4个单位为16k的内存作为压缩结果流缓存
    gzip_buffers 4 16k;
    #设置识别HTTP协议版本号，默认是1.1
    gzip_http_version 1.1;
    #gzip压缩比，可在1~9中设置，1压缩比最小，速度最快。9压缩比最大。速度最慢，消耗CPU
    gzip_comp_level 2;
    #压缩的类型
    gzip_types text/plain application/x-javascript text/css application/xml;
    #让前端的缓存server混村经过的gzip压缩的页面
    gzip_vary   on;

    upstream mycluster{
        server 172.16.119.102:8080 weight=1;
        server 172.16.119.103:8080 weight=1;
    }

    server{
        listen 8089;
        server_name 172.16.119.100;
        charset    utf-8; #设置编码为utf-8
        #root   html;

        #location / {
        #    root   html;
        #    index  index.html index.htm;
        #}

        #location ~ .*\.(jsp|do|action)$
        location / {
            proxy_next_upstream http_502 http_504 error timeout invalid_header;
            proxy_pass http://mycluster;
            # 真实的clientIP
            proxy_set_header   X-Real-IP        $remote_addr;
            # 请求头中Host信息
            proxy_set_header   Host             $host;
            # 代理路由信息。此处取IP有安全隐患
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
            # 真实的用户訪问协议
            proxy_set_header   X-Forwarded-Proto $scheme;
        }
        #静态文件交给nginx处理
        location ~ .*\.(htm|html|gif|jpg|jpeg|png|bmp|swf|ioc|rar|zip|txt|flv|mid|doc|ppt|pdf|xls|mp3|wma)$
        {
            root /usr/local/apache-tomcat-8.5.23/webapps;
            expires 30d;
        }
        #静态文件交给nginx处理
        location ~ .*\.(js|css)?
        {
            root /usr/local/apache-tomcat-8.5.23/webapps;
            expires 1h;
        }
        error_page   500 502 503 504  /50x.html;

        location = /50x.html {
            root   html;
        }

    }

Keepalived configuration
------------------------
Keepalived version       : 1.4.2
Compiler                 : gcc
Preprocessor flags       : 
Compiler flags           : -Wall -Wunused -Wstrict-prototypes -Wextra -g -O2 -fPIE -D_GNU_SOURCE
Linker flags             : -pie
Extra Lib                :  -lcrypto  -lssl 
Use IPVS Framework       : Yes
IPVS use libnl           : No
IPVS syncd attributes    : No
IPVS 64 bit stats        : No
fwmark socket support    : Yes
Use VRRP Framework       : Yes
Use VRRP VMAC            : Yes
Use VRRP authentication  : Yes
With ip rules/routes     : Yes
SNMP vrrp support        : No
SNMP checker support     : No
SNMP RFCv2 support       : No
SNMP RFCv3 support       : No
DBUS support             : No
SHA1 support             : No
Use Debug flags          : No
smtp-alert debugging     : No
Use Json output          : No
Stacktrace support       : No
Memory alloc check       : No
libnl version            : None
Use IPv4 devconf         : No
Use libiptc              : No
Use libipset             : No
init type                : systemd
Build genhash            : Yes
Build documentation      : No

mkdir -p /etc/keepalived
cp /home/hadoop/apps/keepalived/etc/keepalived/keepalived.conf  /etc/keepalived

vim /etc/keepalived/keepalived.conf

vrrp_script chk_nginx {  
 script "/home/hadoop/apps/keepalived-1.4.5/check_nginx.sh" //检测nginx进程的脚本  
 interval 2  
 weight -20  
}  

global_defs {  
 notification_email {  
      //可以添加邮件提醒  
 }  
}  
vrrp_instance VI_1 {  
 state MASTER //主服务器  
 interface et  
 virtual_router_id 51   
 mcast_src_ip 172.16.119.100  
 priority 250   
 advert_int 1  

 authentication {  
        auth_type PASS  
        auth_pass 123456  
 }  
 track_script {  
        chk_nginx  
 }  
 virtual_ipaddress {  
        172.16.119.200  
 }  
}  

cd /home/hadoop/apps/keepalived/sbin
./keepalived -D

vrrp_script chk_nginx {  
 script "/home/hadoop/apps/keepalived-1.4.5/check_nginx.sh" //检测nginx进程的脚本  
 interval 2  
 weight -20  
}  

global_defs {  
 notification_email {  
      //可以添加邮件提醒  
 }  
}  
vrrp_instance VI_1 {  
 state BACKUP //从服务器  
 interface eth1
 virtual_router_id 51   
 mcast_src_ip 172.16.119.101  
 priority 240   
 advert_int 1  

 authentication {  
        auth_type PASS  
        auth_pass 123456  
 }  
 track_script {  
        chk_nginx  
 }  
 virtual_ipaddress {  
        172.16.119.200  
 }  
}  

vrrp_script chk_nginx {  
 script "/home/hadoop/apps/keepalived-1.4.5/check_nginx.sh"//检测nginx进程的脚本  
 interval 2  
 weight -20  
}  

global_defs {  
 notification_email {  
      //可以添加邮件提醒  
 }  
}  
vrrp_instance VI_1 {  
 state BACKUP //主服务器（非抢占模式需要配置成BACKUP）  
 interface eth0  
 virtual_router_id 51   
 mcast_src_ip 172.16.119.100  
 priority 250  
 advert_int 1  
 nopreempt //非抢占模式
 authentication {  
        auth_type PASS  
        auth_pass 123456  
 }  
 track_script {  
        chk_nginx  
 }  
 virtual_ipaddress {  
        172.16.119.200  
 }  
}  

vrrp_script chk_nginx {  
 script "/home/hadoop/apps/keepalived-1.4.5/check_nginx.sh"//检测nginx进程的脚本  
 interval 2  
 weight -20  
}  

global_defs {  
 notification_email {  
      //可以添加邮件提醒  
 }  
}  
vrrp_instance VI_1 {  
 state BACKUP //主服务器（非抢占模式需要配置成BACKUP）  
 interface eth1  
 virtual_router_id 51   
 mcast_src_ip 172.16.119.100  
 priority 240  
 advert_int 1  
 nopreempt //非抢占模式
 authentication {  
        auth_type PASS  
        auth_pass 123456  
 }  
 track_script {  
        chk_nginx  
 }  
 virtual_ipaddress {  
        172.16.119.200  
 }  
}