Keepalived+Nginx+Tomcat 實現高可用Web集羣

時間  2019-11-07
標籤 keepalived+nginx+tomcat keepalived nginx tomcat 實現 可用 web 集羣 欄目 負載均衡 简体版
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title: Keepalived+Nginx+Tomcat 實現高可用Web集羣

集羣規劃圖片

1、Nginx的安裝過程

1.下載Nginx安裝包，安裝依賴環境包

(1)安裝 C++編譯環境

yum  -y install gcc   #C++
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(2)安裝pcre

yum  -y install pcre-devel
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(3)安裝zlib

yum  -y install  zlib-devel
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(4)安裝Nginx

定位到nginx 解壓文件位置，執行編譯安裝命令nginx

[root@localhost nginx-1.12.2]# pwd
/usr/local/nginx/nginx-1.12.2
[root@localhost nginx-1.12.2]# ./configure && make && make install
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(5)啓動Nginx

安裝完成後先尋找那安裝完成的目錄位置web

[root@localhost nginx-1.12.2]# whereis nginx
nginx: /usr/local/nginx
[root@localhost nginx-1.12.2]# 
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進入Nginx子目錄sbin啓動Nginxvim

[root@localhost sbin]# ls
nginx
[root@localhost sbin]# ./nginx &
[1] 5768
[root@localhost sbin]# 
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查看Nginx是否啓動 tomcat

Niginx啓動成功截圖
或經過進程查看Nginx啓動狀況 

[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]# 
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到此Nginx安裝完成並啓動成功。bash

(6)Nginx快捷啓動和開機啓動配置

編輯Nginx快捷啓動腳本【注意Nginx安裝路徑，須要根據本身的NGINX路徑進行改動】服務器

[root@localhost init.d]# vim /etc/rc.d/init.d/nginx
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#!/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
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爲啓動腳本受權 並加入開機啓動負載均衡

[root@localhost init.d]# chmod -R 777 /etc/rc.d/init.d/nginx 
[root@localhost init.d]# chkconfig nginx 
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啓動Nginxjsp

[root@localhost init.d]# ./nginx start
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將Nginx加入系統環境變量oop

[root@localhost init.d]# echo 'export PATH=$PATH:/usr/local/nginx/sbin'>>/etc/profile && source /etc/profile
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Nginx命令 [ service nginx (start|stop|restart) ]ui

[root@localhost init.d]# service nginx start
Starting nginx (via systemctl):                            [  肯定  ]
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Tips:快捷命令

service nginx (start|stop|restart)
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2、KeepAlived安裝和配置

1.安裝Keepalived依賴環境

yum install -y popt-devel     
yum install  -y ipvsadm
yum install -y libnl*
yum install -y libnf*
yum install -y openssl-devel
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2.編譯Keepalived並安裝

[root@localhost keepalived-1.3.9]# ./configure
[root@localhost keepalived-1.3.9]# make && make install
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3.將Keepalive 安裝成系統服務

[root@localhost etc]# mkdir /etc/keepalived
[root@localhost etc]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
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手動複製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/
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爲keepalived 建立軟連接

[root@localhost sysconfig]# ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin/
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設置Keepalived開機自啓動

[root@localhost sysconfig]# chkconfig keepalived on
注意：正在將請求轉發到「systemctl enable keepalived.service」。
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service
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啓動Keepalived服務

[root@localhost keepalived]# keepalived -D -f /etc/keepalived/keepalived.conf

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關閉Keepalived服務

[root@localhost keepalived]# killall keepalived
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3、集羣規劃和搭建

集羣規劃圖片

環境準備：
CentOS 7.2
Keepalived   Version 1.4.0 - December 29, 2017
Nginx           Version: nginx/1.12.2
Tomcat         Version:8

集羣規劃清單

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，用於標識切換Web

更改TomcatServer01 節點ROOT/index.jsp 信息，加入TomcatIP地址，並加入Nginx值，即修改節點192.168.43.103信息以下：

<div id="asf-box">
    <h1>${pageContext.servletContext.serverInfo}(192.168.224.103)<%=request.getHeader("X-NGINX")%></h1>
</div>
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更改TomcatServer02 節點ROOT/index.jsp信息，加入TomcatIP地址，並加入Nginx值，即修改節點192.168.43.104信息以下：

<div id="asf-box">
    <h1>${pageContext.servletContext.serverInfo}(192.168.224.104)<%=request.getHeader("X-NGINX")%></h1>
</div>
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2.啓動Tomcat服務，查看Tomcat服務IP信息，此時Nginx未啓動，所以request-header沒有Nginx信息。

Tomcat啓動信息

3.配置Nginx代理信息

1.配置Master節點[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";
   }
   #......其餘省略
}
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2.配置Backup節點[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";
    }
    #......其餘省略
}
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3.啓動Master 節點Nginx服務

[root@localhost init.d]# service nginx start
Starting nginx (via systemctl):                            [  肯定  ]
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此時訪問 192.168.43.101 能夠看到103和104節點Tcomat交替顯示，說明Nginx服務已經將請求負載到了2臺tomcat上。

Nginx 負載效果

4.同理配置Backup[192.168.43.102] Nginx信息，啓動Nginx後，訪問192.168.43.102後能夠看到Backup節點已起到負載的效果。

Backup負載效果

4.配置Keepalived 腳本信息

1.在Master節點和Slave節點 /etc/keepalived目錄下添加check_nginx.sh 文件，用於檢測Nginx的存貨情況，添加keepalived.conf文件

check_nginx.sh文件信息以下：

#!/bin/bash
#時間變量，用於記錄日誌
d=`date --date today +%Y%m%d_%H:%M:%S`
#計算nginx進程數量
n=`ps -C nginx --no-heading|wc -l`
#若是進程爲0，則啓動nginx，而且再次檢測nginx進程數量，
#若是還爲0，說明nginx沒法啓動，此時須要關閉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

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添加完成後，爲check_nginx.sh 文件受權，便於腳本得到執行權限。

[root@localhost keepalived]# chmod -R 777 /etc/keepalived/check_nginx.sh 

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2.在Master 節點 /etc/keepalived目錄下，添加keepalived.conf 文件，具體信息以下：

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 {  
     //能夠添加郵件提醒  
 }  
}  
vrrp_instance VI_1 {  
 state MASTER                  #標示狀態爲MASTER 備份機爲BACKUP
 interface ens33               #設置實例綁定的網卡(ip addr查看，須要根據我的網卡綁定)
 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權重要高於BACKUP 好比BACKUP爲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                     #非搶佔模式
 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         #能夠多個虛擬IP，換行便可
 }  
}
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3.在Backup節點 etc/keepalived目錄下添加 keepalived.conf 配置文件

信息以下：

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 {  
     //能夠添加郵件提醒  
 }  
}  
vrrp_instance VI_1 {  
 state BACKUP                  #標示狀態爲MASTER 備份機爲BACKUP
 interface ens33               #設置實例綁定的網卡(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權重要高於BACKUP 好比BACKUP爲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                     #非搶佔模式
 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         #能夠多個虛擬IP，換行便可
 }  
}
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Tips:關於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 - 這個是網卡名，我使用的是VM12.0的版本，因此這裏網卡名爲ens33
  • mcast_src_ip - 配置各自的實際IP地址
  • priority - 主服務器的優先級必須比從服務器的高，這裏主服務器配置成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靠這個來通訊
  • virtual_router_id - 主從服務器必須保持一致

5.集羣高可用(HA)驗證

  • Step1 啓動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
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查看服務啓動進程

[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

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查看Keepalived啓動進程

[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

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使用 ip add 查看虛擬IP綁定狀況，如出現192.168.43.150 節點信息則綁定到Master節點

[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
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  • Step 2 啓動Backup節點Nginx服務和Keepalived服務，查看服務啓動狀況，如Backup節點出現了虛擬IP，則Keepalvied配置文件有問題，此狀況稱爲腦裂。
[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

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  • Step 3 驗證服務
    瀏覽並屢次強制刷新地址： http://192.168.43.150 ,能夠看到103和104屢次交替顯示，並顯示Nginx-1,則代表 Master節點在進行web服務轉發。
  • Step 4 關閉Master keepalived服務和Nginx服務，訪問Web服務觀察服務轉移狀況
[root@localhost keepalived]# killall keepalived
[root@localhost keepalived]# service nginx stop
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此時強制刷新192.168.43.150發現 頁面交替顯示103和104並顯示Nginx-2 ，VIP已轉移到192.168.43.102上，已證實服務自動切換到備份節點上。

  • Step 5 啓動Master Keepalived 服務和Nginx服務
    此時再次驗證發現，VIP已被Master從新奪回，並頁面交替顯示 103和104，此時顯示Nginx-1

4、Keepalived搶佔模式和非搶佔模式

keepalived的HA分爲搶佔模式和非搶佔模式，搶佔模式即MASTER從故障中恢復後，會將VIP從BACKUP節點中搶佔過來。非搶佔模式即MASTER恢復後不搶佔BACKUP升級爲MASTER後的VIP。
非搶佔模式配置：

  • 1> 在vrrp_instance塊下兩個節點各增長了nopreempt指令，表示不爭搶vip
  • 2> 節點的state都爲BACKUP 兩個keepalived節點都啓動後，默認都是BACKUP狀態，雙方在發送組播信息後，會根據優先級來選舉一個MASTER出來。因爲二者都配置了nopreempt，因此MASTER從故障中恢復後，不會搶佔vip。這樣會避免VIP切換可能形成的服務延遲。
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