nginx+keepalived configuration of a high-availability Web cluster for CentOS Linux load Balancing

Nginx+keepalived implements a load-balanced, highly available WEB Services cluster,Nginx as a load balancer,keepalived as highly available when one of the load balancers ( Nginx) can quickly switch to an alternate load balancer (nginx) in the event of a failure tomaintain business continuity.

1 , Server environment configuration and IP Distribution

Operating System: CentOS Release 6.7 (Final)

Nginx version:nginx/1.8.0

keepalived version:keepalived v1.2.13

IP Allocation Table for Nginx + keepalived server

Server name IP Role

DR1 192.168.171.10 provides load balancing

DR2 192.168.171.20 provides load balancing

VIP address of 192.168.171.100 website

RS1 192.168.171.30 provides web services

RS2 192.168.171.40 provides web services

2 , respectively, in DR1 and DR2 install Nginx on load balancer and related scripts

1), add the user group running nginxd www and nginx storage log location, and install gcc Base library (using yum installation)

Yum install-y make apr* autoconf automakecurl curl-devel gcc gcc-c++ gtk+-devel zlib-devel OpenSSL Openssl-develpcre-deve L GD kernel keyutils patch perl kernel-headers compat* cpp glibc libgomp libstdc++-develkeyutils-libs-devel Libsepol-deve L libselinux-devel krb5-devel libxpm* freetype freetype-devel freetype*fontconfig fontconfig-devel libjpeg*libpng* php- Common PHP-GD gettext gettext-devel ncurses* libtool* libxml2libxml2-devel patch policycoreutils Bison pcre pece-devel

Groupadd www # creating groups

Groupadd–g www www # create www user and join www group

mkdir–p/data/logs/# directory where logs are stored

Chown R www.www/data/logs/# Modify owner and owning group

2), download and install ngixn-1.8.0, download to /usr/local/src/ directory by default

Cd/usr/local/src

wget http://nginx.org/download/nginx-1.8.0.tar.gz # Download nginx

Tar zxvf nginx-1.8.0.tar.gz

CD nginx-1.8.0

./configure--prefix=/usr/local/nginx--with-http_realip_module--with-http_sub_module--with-http_gzip_static_ Module--with-http_stub_status_module--with-pcre--with-http_ssl_module

Make && make install

3), configuration nginx, the default configuration file is in the/usr/local/nginx/conf/nginx.conf

Vim/usr/local/nginx/conf/nginx.conf

User www www; # users to use

Worker_processes 2;

Error_log/usr/local/nginx/logs/nginx_error.log Crit;

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

Worker_rlimit_nofile 51200;

Events

{

Use Epoll;

Worker_connections 6000;

}

http

{

Include Mime.types;

Default_type Application/octet-stream;

Server_names_hash_bucket_size 3526;

Server_names_hash_max_size 4096;

Log_format combined_realip ' $remote _addr $http _x_forwarded_for[$time _local] '

' $host ' $request _uri "$status"

' "$http _referer" "$http _user_agent"; # format of the log

Sendfile on;

Tcp_nopush on;

Keepalive_timeout 30;

Client_header_timeout 3m;

Client_body_timeout 3m;

Send_timeout 3m;

Connection_pool_size 256;

Client_header_buffer_size 1k;

Large_client_header_buffers 8 4k;

Request_pool_size 4k;

Output_buffers 4 32k;

Postpone_output 1460;

Client_max_body_size 10m;

Client_body_buffer_size 256k;

Client_body_temp_path/usr/local/nginx/client_body_temp;

Proxy_temp_path/usr/local/nginx/proxy_temp;

Fastcgi_temp_path/usr/local/nginx/fastcgi_temp;

Fastcgi_intercept_errors on;

Tcp_nodelay on;

gzip on;

Gzip_min_length 1k;

Gzip_buffers 4 8k;

Gzip_comp_level 5;

Gzip_http_version 1.1;

Gzip_types text/plain application/x-javascript text/css text/htmapplication/xml;

# Define a Load Balancer configuration module

Upstream MyServer {

Ip_hash; #测试的时候建议注释掉

Server 192.168.171.30:80 weight=1 max_fails=3 fail_timeout=20s;

Server 192.168.171.40:80 weight=1 max_fails=3 fail_timeout=20s;

}

server {

Listen 80;

server_name www.balichlb.org;

Index index.htm index.html;

Location/{

Proxy_pass http://MyServer;

Proxy_set_header Host $Host;

Proxy_next_upstream errortimeout http_500 http_502 http_504;

Proxy_read_timeout 10s;

Proxy_set_header x-real-ip$remote_addr;

Proxy_set_header x-forwarded-for$proxy_add_x_forwarded_for;

}

Access_log/data/lgos/access.log Combined_realip; # access to logs

}

}

Executed in two nginx(DR1 and DR2):/usr/local/nginx/sbin/nginx command to start nginx service, Then use the lsof–i:80 command to check (and of course you can write nginx startup scripts)

Vim/etc/init.d/nginx # Writing nginx startup, shutdown, script

#!/bin/bash

# Chkconfig:-30 21

# Description:http Service.

# Source Function Library

. /etc/init.d/functions

# Nginx Settings

Nginx_sbin= "/usr/local/nginx/sbin/nginx"

nginx_conf= "/usr/local/nginx/conf/nginx.conf"

Nginx_pid= "/usr/local/nginx/logs/nginx.pid"

Retval=0

Prog= "Nginx"

Start () {

Echo-n $ "Starting $prog:"

Mkdir-p/dev/shm/nginx_temp

Daemon $NGINX _sbin-c $NGINX _conf

Retval=$?

Echo

Return $RETVAL

}

Stop () {

Echo-n $ "Stopping $prog:"

Killproc-p $NGINX _pid $NGINX _sbin-term

Rm-rf/dev/shm/nginx_temp

Retval=$?

Echo

Return $RETVAL

}

Reload () {

Echo-n $ "Reloading $prog:"

Killproc-p $NGINX _pid $NGINX _sbin-hup

Retval=$?

Echo

Return $RETVAL

}

Restart () {

Stop

Start

}

Configtest () {

$NGINX _sbin-c $NGINX _conf-t

return 0

}

Case "$" in

Start

Start

;;

Stop

Stop

;;

Reload

Reload

;;

Restart

Restart

;;

Configtest)

Configtest

;;

*)

echo $ "Usage: $0{start|stop|reload|restart|configtest}"

Retval=1

Esac

Exit $RETVAL

: Wq Save exit.

chmod 755/etc/init.d/nginx # Modify Permissions

Chkconfig--add Nginx # Add system Services list

/etc/init.d/nginx Start # launch nginx service

3 , installation keepalived , make it a web and nginx the HA (High availability)

Yum Install keepalived

1), keepalived configuration files, respectively, configured on the master and the Nginx , by default in the/etc/keepalived/keepalived.conf

Configure on The main nginx first :

Vim/etc/keepalived/keepalived.conf

! Configuration File for Keepalived

# Global Definition Section

Global_defs {

Notification_email {

[Email protected]

}

Notification_email_from [email protected]

Smtp_server 127.0.0.1

Smtp_connect_timeout 30

router_id Lvs_devel

}

Vrrp_instance Vi_1 {

State Master # master server is Master, standby server is backup

Interface eth0

VIRTUAL_ROUTER_ID 51

MCAST_SRC_IP 192.168.171.10 # The IP address of the main nginx Service

Priority 100

Advert_int 1

Authentication {

Auth_type PASS

Auth_pass 1111

}

virtual_ipaddress {

192.168.171.100 # Set a virtual IP address, can be multiple, one line at a

}

}

The configuration of the alternate server row is basically the same, and the place to be modified is as follows:

State MASTER >> State BACKUP

Priority >> Priority # modified to less than the primary server

Mcast_src_ip 192.168.171.10 >>mcast_src_ip 192.168.171.20 # Alternate ngixn IP

Start the keepalived Service (Guthrie) on two load balancers, respectively

/etc/init.d/keepalived start

You can view the startup of keepalived through log information, at which point a VIP is bound to eth0:0 on the main nginx .

now Nginx can indeed load balance the backend web services, but if the Nginx service fails,the keepalived service is still running, unable to The VIP is transferred to the standby server. This can be accomplished using the following script:

vim/etc/keepalived/nginx_pid.sh

#!/bin/bash

While:

Do

Nginxpid= ' ps-c nginx--no-header |wc-l '

if[$nginxpid-eq 0];then

/etc/init.d/nginxstart

Sleep 3

if[$nginxpid-eq 0];then

/etc/init.d/keepalivedstop

Fi

Fi

Sleep 5

Done

put it in the background to run:nohup/bin/bash/etc/keepalived/nginx_pid.sh &

4 , analog failure

1), close The service of the main nginx, test whether the script can let the normal operation. Turn off The keepalived service between the switch is OK.

2), after the main nginx service repair, restart the keepalived service After the start, can re-take over the service.

3), directly disconnect the network, view the service.

This article is from the "Balich" blog, make sure to keep this source http://balich.blog.51cto.com/6641781/1716138

nginx+keepalived configuration of a high-availability Web cluster for CentOS Linux load Balancing