Keepalived+Nginx+Tomcat 實現(xiàn)高可用Web集群的示例代碼
Keepalived+Nginx+Tomcat 實現(xiàn)高可用Web集群

一、Nginx的安裝過程
1.下載Nginx安裝包,安裝依賴環(huán)境包
(1)安裝 C++編譯環(huán)境
yum -y install gcc #C++
(2)安裝pcre
yum -y install pcre-devel
(3)安裝zlib
yum -y install zlib-devel
(4)安裝Nginx
定位到nginx 解壓文件位置,執(zhí)行編譯安裝命令
[root@localhost nginx-1.12.2]# pwd /usr/local/nginx/nginx-1.12.2 [root@localhost nginx-1.12.2]# ./configure && make && make install
(5)啟動Nginx
安裝完成后先尋找那安裝完成的目錄位置
[root@localhost nginx-1.12.2]# whereis nginx nginx: /usr/local/nginx [root@localhost nginx-1.12.2]#
進入Nginx子目錄sbin啟動Nginx
[root@localhost sbin]# ls nginx [root@localhost sbin]# ./nginx & [1] 5768 [root@localhost sbin]#
查看Nginx是否啟動

或通過進程查看Nginx啟動情況
[root@localhost sbin]# ps -aux|grep nginx root 5769 0.0 0.0 20484 608 ? Ss 14:03 0:00 nginx: master process ./nginx nobody 5770 0.0 0.0 23012 1620 ? S 14:03 0:00 nginx: worker process root 5796 0.0 0.0 112668 972 pts/0 R+ 14:07 0:00 grep --color=auto nginx [1]+ 完成 ./nginx [root@localhost sbin]#
到此Nginx安裝完成并啟動成功。
(6)Nginx快捷啟動和開機啟動配置
編輯Nginx快捷啟動腳本【 注意Nginx安裝路徑 , 需要根據(jù)自己的NGINX路徑進行改動 】
[root@localhost init.d]# vim /etc/rc.d/init.d/nginx
#!/bin/sh
#
# nginx - this script starts and stops the nginx daemon
#
# chkconfig: - 85 15
# description: Nginx is an HTTP(S) server, HTTP(S) reverse \
# proxy and IMAP/POP3 proxy server
# processname: nginx
# config: /etc/nginx/nginx.conf
# config: /usr/local/nginx/conf/nginx.conf
# pidfile: /usr/local/nginx/logs/nginx.pid
# Source function library.
. /etc/rc.d/init.d/functions
# Source networking configuration.
. /etc/sysconfig/network
# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0
nginx="/usr/local/nginx/sbin/nginx"
prog=$(basename $nginx)
NGINX_CONF_FILE="/usr/local/nginx/conf/nginx.conf"
[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx
lockfile=/var/lock/subsys/nginx
make_dirs() {
# make required directories
user=`$nginx -V 2>&1 | grep "configure arguments:" | sed 's/[^*]*--user=\([^ ]*\).*/\1/g' -`
if [ -z "`grep $user /etc/passwd`" ]; then
useradd -M -s /bin/nologin $user
fi
options=`$nginx -V 2>&1 | grep 'configure arguments:'`
for opt in $options; do
if [ `echo $opt | grep '.*-temp-path'` ]; then
value=`echo $opt | cut -d "=" -f 2`
if [ ! -d "$value" ]; then
# echo "creating" $value
mkdir -p $value && chown -R $user $value
fi
fi
done
}
start() {
[ -x $nginx ] || exit 5
[ -f $NGINX_CONF_FILE ] || exit 6
make_dirs
echo -n $"Starting $prog: "
daemon $nginx -c $NGINX_CONF_FILE
retval=$?
echo
[ $retval -eq 0 ] && touch $lockfile
return $retval
}
stop() {
echo -n $"Stopping $prog: "
killproc $prog -QUIT
retval=$?
echo
[ $retval -eq 0 ] && rm -f $lockfile
return $retval
}
restart() {
#configtest || return $?
stop
sleep 1
start
}
reload() {
#configtest || return $?
echo -n $"Reloading $prog: "
killproc $nginx -HUP
RETVAL=$?
echo
}
force_reload() {
restart
}
configtest() {
$nginx -t -c $NGINX_CONF_FILE
}
rh_status() {
status $prog
}
rh_status_q() {
rh_status >/dev/null 2>&1
}
case "$1" in
start)
rh_status_q && exit 0
$1
;;
stop)
rh_status_q || exit 0
$1
;;
restart|configtest)
$1
;;
reload)
rh_status_q || exit 7
$1
;;
force-reload)
force_reload
;;
status)
rh_status
;;
condrestart|try-restart)
rh_status_q || exit 0
;;
*)
echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"
exit 2
esac
為啟動腳本授權 并加入開機啟動
[root@localhost init.d]# chmod -R 777 /etc/rc.d/init.d/nginx [root@localhost init.d]# chkconfig nginx
啟動Nginx
[root@localhost init.d]# ./nginx start
將Nginx加入系統(tǒng)環(huán)境變量
[root@localhost init.d]# echo 'export PATH=$PATH:/usr/local/nginx/sbin'>>/etc/profile && source /etc/profile
Nginx命令 [ service nginx (start|stop|restart) ]
[root@localhost init.d]# service nginx start Starting nginx (via systemctl): [ 確定 ]
Tips: 快捷命令
service nginx (start|stop|restart)
二、KeepAlived安裝和配置
1.安裝Keepalived依賴環(huán)境
yum install -y popt-devel yum install -y ipvsadm yum install -y libnl* yum install -y libnf* yum install -y openssl-devel
2.編譯Keepalived并安裝
[root@localhost keepalived-1.3.9]# ./configure [root@localhost keepalived-1.3.9]# make && make install
3.將Keepalive 安裝成系統(tǒng)服務
[root@localhost etc]# mkdir /etc/keepalived [root@localhost etc]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
手動復制默認的配置文件到默認路徑
[root@localhost etc]# mkdir /etc/keepalived [root@localhost etc]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ [root@localhost etc]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
為keepalived 創(chuàng)建軟鏈接
[root@localhost sysconfig]# ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin/
設置Keepalived開機自啟動
[root@localhost sysconfig]# chkconfig keepalived on 注意:正在將請求轉發(fā)到“systemctl enable keepalived.service”。 Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service
啟動Keepalived服務
[root@localhost keepalived]# keepalived -D -f /etc/keepalived/keepalived.conf
關閉Keepalived服務
[root@localhost keepalived]# killall keepalived
三、集群規(guī)劃和搭建

環(huán)境準備:
CentOS 7.2
Keepalived Version 1.4.0 - December 29, 2017
Nginx Version: nginx/1.12.2
Tomcat Version:8
集群規(guī)劃清單
| 虛擬機 | IP | 說明 |
|---|---|---|
| Keepalived+Nginx1[Master] | 192.168.43.101 | Nginx Server 01 |
| Keeepalived+Nginx[Backup] | 192.168.43.102 | Nginx Server 02 |
| Tomcat01 | 192.168.43.103 | Tomcat Web Server01 |
| Tomcat02 | 192.168.43.104 | Tomcat Web Server02 |
| VIP | 192.168.43.150 | 虛擬漂移IP |
1.更改Tomcat默認歡迎頁面,用于標識切換Web
更改TomcatServer01 節(jié)點ROOT/index.jsp 信息,加入TomcatIP地址,并加入Nginx值,即修改節(jié)點192.168.43.103信息如下:
<div id="asf-box">
<h1>${pageContext.servletContext.serverInfo}(192.168.224.103)<%=request.getHeader("X-NGINX")%></h1>
</div>
更改TomcatServer02 節(jié)點ROOT/index.jsp信息,加入TomcatIP地址,并加入Nginx值,即修改節(jié)點192.168.43.104信息如下:
<div id="asf-box">
<h1>${pageContext.servletContext.serverInfo}(192.168.224.104)<%=request.getHeader("X-NGINX")%></h1>
</div>
2.啟動Tomcat服務,查看Tomcat服務IP信息,此時Nginx未啟動,因此request-header沒有Nginx信息。

3.配置Nginx代理信息
1.配置Master節(jié)點[192.168.43.101]代理信息
upstream tomcat {
server 192.168.43.103:8080 weight=1;
server 192.168.43.104:8080 weight=1;
}
server{
location / {
proxy_pass http://tomcat;
proxy_set_header X-NGINX "NGINX-1";
}
#......其他省略
}
2.配置Backup節(jié)點[192.168.43.102]代理信息
upstream tomcat {
server 192.168.43.103:8080 weight=1;
server 192.168.43.104:8080 weight=1;
}
server{
location / {
proxy_pass http://tomcat;
proxy_set_header X-NGINX "NGINX-2";
}
#......其他省略
}
3.啟動Master 節(jié)點Nginx服務
[root@localhost init.d]# service nginx start Starting nginx (via systemctl): [ 確定 ]
此時訪問 192.168.43.101 可以看到103和104節(jié)點Tcomat交替顯示,說明Nginx服務已經將請求負載到了2臺tomcat上。

4.同理配置Backup[192.168.43.102] Nginx信息,啟動Nginx后,訪問192.168.43.102后可以看到Backup節(jié)點已起到負載的效果。

4.配置Keepalived 腳本信息
1. 在Master節(jié)點和Slave節(jié)點 /etc/keepalived目錄下添加check_nginx.sh 文件,用于檢測Nginx的存貨狀況,添加keepalived.conf文件
check_nginx.sh文件信息如下:
#!/bin/bash
#時間變量,用于記錄日志
d=`date --date today +%Y%m%d_%H:%M:%S`
#計算nginx進程數(shù)量
n=`ps -C nginx --no-heading|wc -l`
#如果進程為0,則啟動nginx,并且再次檢測nginx進程數(shù)量,
#如果還為0,說明nginx無法啟動,此時需要關閉keepalived
if [ $n -eq "0" ]; then
/etc/rc.d/init.d/nginx start
n2=`ps -C nginx --no-heading|wc -l`
if [ $n2 -eq "0" ]; then
echo "$d nginx down,keepalived will stop" >> /var/log/check_ng.log
systemctl stop keepalived
fi
fi
添加完成后,為check_nginx.sh 文件授權,便于腳本獲得執(zhí)行權限。
[root@localhost keepalived]# chmod -R 777 /etc/keepalived/check_nginx.sh
2.在Master 節(jié)點 /etc/keepalived目錄下,添加keepalived.conf 文件,具體信息如下:
vrrp_script chk_nginx {
script "/etc/keepalived/check_nginx.sh" //檢測nginx進程的腳本
interval 2
weight -20
}
global_defs {
notification_email {
//可以添加郵件提醒
}
}
vrrp_instance VI_1 {
state MASTER #標示狀態(tài)為MASTER 備份機為BACKUP
interface ens33 #設置實例綁定的網(wǎng)卡(ip addr查看,需要根據(jù)個人網(wǎng)卡綁定)
virtual_router_id 51 #同一實例下virtual_router_id必須相同
mcast_src_ip 192.168.43.101
priority 250 #MASTER權重要高于BACKUP 比如BACKUP為240
advert_int 1 #MASTER與BACKUP負載均衡器之間同步檢查的時間間隔,單位是秒
nopreempt #非搶占模式
authentication { #設置認證
auth_type PASS #主從服務器驗證方式
auth_pass 123456
}
track_script {
check_nginx
}
virtual_ipaddress { #設置vip
192.168.43.150 #可以多個虛擬IP,換行即可
}
}
3.在Backup節(jié)點 etc/keepalived目錄下添加 keepalived.conf 配置文件
信息如下:
vrrp_script chk_nginx {
script "/etc/keepalived/check_nginx.sh" //檢測nginx進程的腳本
interval 2
weight -20
}
global_defs {
notification_email {
//可以添加郵件提醒
}
}
vrrp_instance VI_1 {
state BACKUP #標示狀態(tài)為MASTER 備份機為BACKUP
interface ens33 #設置實例綁定的網(wǎng)卡(ip addr查看)
virtual_router_id 51 #同一實例下virtual_router_id必須相同
mcast_src_ip 192.168.43.102
priority 240 #MASTER權重要高于BACKUP 比如BACKUP為240
advert_int 1 #MASTER與BACKUP負載均衡器之間同步檢查的時間間隔,單位是秒
nopreempt #非搶占模式
authentication { #設置認證
auth_type PASS #主從服務器驗證方式
auth_pass 123456
}
track_script {
check_nginx
}
virtual_ipaddress { #設置vip
192.168.43.150 #可以多個虛擬IP,換行即可
}
}
Tips: 關于配置信息的幾點說明
- state - 主服務器需配成MASTER,從服務器需配成BACKUP
- interface - 這個是網(wǎng)卡名,我使用的是VM12.0的版本,所以這里網(wǎng)卡名為ens33
- mcast_src_ip - 配置各自的實際IP地址
- priority - 主服務器的優(yōu)先級必須比從服務器的高,這里主服務器配置成250,從服務器配置成240
- virtual_ipaddress - 配置虛擬IP(192.168.43.150)
- authentication - auth_pass主從服務器必須一致,keepalived靠這個來通信
- virtual_router_id - 主從服務器必須保持一致
5.集群高可用(HA)驗證
Step1 啟動Master機器的Keepalived和 Nginx服務
[root@localhost keepalived]# keepalived -D -f /etc/keepalived/keepalived.conf [root@localhost keepalived]# service nginx start
查看服務啟動進程
[root@localhost keepalived]# ps -aux|grep nginx root 6390 0.0 0.0 20484 612 ? Ss 19:13 0:00 nginx: master process /usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf nobody 6392 0.0 0.0 23008 1628 ? S 19:13 0:00 nginx: worker process root 6978 0.0 0.0 112672 968 pts/0 S+ 20:08 0:00 grep --color=auto nginx
查看Keepalived啟動進程
[root@localhost keepalived]# ps -aux|grep keepalived root 6402 0.0 0.0 45920 1016 ? Ss 19:13 0:00 keepalived -D -f /etc/keepalived/keepalived.conf root 6403 0.0 0.0 48044 1468 ? S 19:13 0:00 keepalived -D -f /etc/keepalived/keepalived.conf root 6404 0.0 0.0 50128 1780 ? S 19:13 0:00 keepalived -D -f /etc/keepalived/keepalived.conf root 7004 0.0 0.0 112672 976 pts/0 S+ 20:10 0:00 grep --color=auto keepalived
使用 ip add 查看虛擬IP綁定情況,如出現(xiàn)192.168.43.150 節(jié)點信息則綁定到Master節(jié)點
[root@localhost keepalived]# ip add 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:91:bf:59 brd ff:ff:ff:ff:ff:ff inet 192.168.43.101/24 brd 192.168.43.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.43.150/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::9abb:4544:f6db:8255/64 scope link valid_lft forever preferred_lft forever inet6 fe80::b0b3:d0ca:7382:2779/64 scope link tentative dadfailed valid_lft forever preferred_lft forever inet6 fe80::314f:5fe7:4e4b:64ed/64 scope link tentative dadfailed valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN qlen 1000 link/ether 52:54:00:2b:74:aa brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 1000 link/ether 52:54:00:2b:74:aa brd ff:ff:ff:ff:ff:ff
Step 2 啟動Backup節(jié)點Nginx服務和Keepalived服務,查看服務啟動情況,如Backup節(jié)點出現(xiàn)了虛擬IP,則Keepalvied配置文件有問題,此情況稱為腦裂。
[root@localhost keepalived]# clear [root@localhost keepalived]# ip add 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:14:df:79 brd ff:ff:ff:ff:ff:ff inet 192.168.43.102/24 brd 192.168.43.255 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::314f:5fe7:4e4b:64ed/64 scope link valid_lft forever preferred_lft forever 3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN qlen 1000 link/ether 52:54:00:2b:74:aa brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 1000 link/ether 52:54:00:2b:74:aa brd ff:ff:ff:ff:ff:ff
Step 3 驗證服務
瀏覽并多次強制刷新地址: http://192.168.43.150 ,可以看到103和104多次交替顯示,并顯示Nginx-1,則表明 Master節(jié)點在進行web服務轉發(fā)。
Step 4 關閉Master keepalived服務和Nginx服務,訪問Web服務觀察服務轉移情況
[root@localhost keepalived]# killall keepalived [root@localhost keepalived]# service nginx stop
此時強制刷新192.168.43.150發(fā)現(xiàn) 頁面交替顯示103和104并顯示Nginx-2 ,VIP已轉移到192.168.43.102上,已證明服務自動切換到備份節(jié)點上。
Step 5 啟動Master Keepalived 服務和Nginx服務
此時再次驗證發(fā)現(xiàn),VIP已被Master重新奪回,并頁面交替顯示 103和104,此時顯示Nginx-1
四、Keepalived搶占模式和非搶占模式
keepalived的HA分為搶占模式和非搶占模式,搶占模式即MASTER從故障中恢復后,會將VIP從BACKUP節(jié)點中搶占過來。非搶占模式即MASTER恢復后不搶占BACKUP升級為MASTER后的VIP。
非搶占模式配置:
1> 在vrrp_instance塊下兩個節(jié)點各增加了nopreempt指令,表示不爭搶vip
2> 節(jié)點的state都為BACKUP 兩個keepalived節(jié)點都啟動后,默認都是BACKUP狀態(tài),雙方在發(fā)送組播信息后,會根據(jù)優(yōu)先級來選舉一個MASTER出來。由于兩者都配置了nopreempt,所以MASTER從故障中恢復后,不會搶占vip。這樣會避免VIP切換可能造成的服務延遲。
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持腳本之家。
- keepalived+nginx高可用實現(xiàn)方法示例
- nginx結合keepalived實現(xiàn)高可用的完整步驟
- Keepalived實現(xiàn)Nginx負載均衡高可用的示例代碼
- keepalived對nginx進行高可用搭建及原理詳解
- Keepalived如何實現(xiàn)Nginx高可用
- keepalived?+?nginx?實現(xiàn)高可用方案
- 使用Nginx?+?Keepalived?實現(xiàn)高可用?Web?負載均衡筆記(虛擬機)
- Nginx+keepalived實現(xiàn)七層的負載均衡的高可用(最新解決方案)
- Nginx高可用Keepalived的具體使用
- Nginx使用Keepalived部署web集群(高可用高性能負載均衡)實戰(zhàn)案例
- Keepalived搭建nginx高可用的實現(xiàn)
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