組件及實現的功能
Keepalived：實現對Haproxy服務的高可用，並採用雙主模型配置;
Haproxy：實現對Nginx的負載均衡和讀寫分離;
Nginx：實現對HTTP請求的高速處理;
架構設計圖
重點概念
vrrp_script中節點權重改變算法
vrrp_script 裏的script返回值爲0時認爲檢測成功，其它值都會當成檢測失敗；
weight 爲正時，腳本檢測成功時此weight會加到priority上，檢測失敗時不加；
主失敗:
主 priority < 從 priority + weight 時會切換。
主成功：
主 priority + weight > 從 priority + weight 時，主依然爲主
weight 爲負時，腳本檢測成功時此weight不影響priority，檢測失敗時priority – abs(weight)
主失敗:
主 priority – abs(weight) < 從priority 時會切換主從
主成功:
主 priority > 從priority 主依然爲主
具體解釋詳見博文“Keepalived雙主模型中vrrp_script中權重改變故障排查”
部署配置
Keepalived部署
配置
yum -y install keepalived # 兩節點都需部署
# 172.16.25.109
# vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from [email protected]
smtp_connect_timeout 3
smtp_server 127.0.0.1
router_id LVS_DEVEL
}
vrrp_script chk_maintaince_down {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight 2
}
vrrp_script chk_haproxy {
script "killall -0 haproxy"
interval 1
weight 2
}
vrrp_instance VI_1 {
interface eth0
state MASTER
priority 100
virtual_router_id 125
garp_master_delay 1
authentication {
auth_type PASS
auth_pass 1e3459f77aba4ded
}
track_interface {
eth0
}
virtual_ipaddress {
172.16.25.10/16 dev eth0 label eth0:0
}
track_script {
chk_haproxy
}
notify_master "/etc/keepalived/notify.sh master 172.16.25.10"
notify_backup "/etc/keepalived/notify.sh backup 172.16.25.10"
notify_fault "/etc/keepalived/notify.sh fault 172.16.25.10"
}
vrrp_instance VI_2 {
interface eth0
state BACKUP
priority 99
virtual_router_id 126
garp_master_delay 1
authentication {
auth_type PASS
auth_pass 7615c4b7f518cede
}
track_interface {
eth0
}
virtual_ipaddress {
172.16.25.11/16 dev eth0 label eth0:1
}
track_script {
chk_haproxy
chk_maintaince_down
}
notify_master "/etc/keepalived/notify.sh master 172.16.25.11"
notify_backup "/etc/keepalived/notify.sh backup 172.16.25.11"
notify_fault "/etc/keepalived/notify.sh fault 172.16.25.11"
}
# 172.16.25.110
# vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from [email protected]
smtp_connect_timeout 3
smtp_server 127.0.0.1
router_id LVS_DEVEL
}
vrrp_script chk_maintaince_down {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight 2
}
vrrp_script chk_haproxy {
script "killall -0 haproxy"
interval 1
weight 2
}
vrrp_instance VI_1 {
interface eth0
state BACKUP
priority 99
virtual_router_id 125
garp_master_delay 1
authentication {
auth_type PASS
auth_pass 1e3459f77aba4ded
}
track_interface {
eth0
}
virtual_ipaddress {
172.16.25.10/16 dev eth0 label eth0:0
}
track_script {
chk_haproxy
chk_maintaince_down
}
notify_master "/etc/keepalived/notify.sh master 172.16.25.10"
notify_backup "/etc/keepalived/notify.sh backup 172.16.25.10"
notify_fault "/etc/keepalived/notify.sh fault 172.16.25.10"
}
vrrp_instance VI_2 {
interface eth0
state MASTER
priority 100
virtual_router_id 126
garp_master_delay 1
authentication {
auth_type PASS
auth_pass 7615c4b7f518cede
}
track_interface {
eth0
}
virtual_ipaddress {
172.16.25.11/16 dev eth0 label eth0:1
}
track_script {
chk_haproxy
}
notify_master "/etc/keepalived/notify.sh master 172.16.25.11"
notify_backup "/etc/keepalived/notify.sh backup 172.16.25.11"
notify_fault "/etc/keepalived/notify.sh fault 172.16.25.11"
}
# vi /etc/keepalived/notify.sh
#!/bin/bash
# Author: Jason.Yu <[email protected]>
# description: An example of notify script
#
contact='root@localhost'
notify() {
mailsubject="`hostname` to be $1: $2 floating"
mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"
echo $mailbody | mail -s "$mailsubject" $contact
}
case "$1" in
master)
notify master $2
/etc/rc.d/init.d/haproxy restart
exit 0
;;
backup)
notify backup $2 # 在節點切換成backup狀態時，無需刻意停止haproxy服務，防止chk_maintaince和chk_haproxy多次對haproxy服務操作；
exit 0
;;
fault)
notify fault $2 # 同上
exit 0
;;
*)
echo 'Usage: `basename $0` {master|backup|fault}'
exit 1
;;
esac啓動服務
service keepalived start # 在兩個節點上都需要啓動
keepalived雙主模型啓動
Haproxy部署
安裝配置
yum -y install haproxy # 兩節點都需部署
vi /etc/haproxy/haproxy.cfg # 兩節點配置一致
global
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
daemon # 以後臺程序運行；
defaults
mode http # 選擇HTTP模式，即可進行7層過濾；
log global
option httplog # 可以得到更加豐富的日誌輸出；
option dontlognull
option http-server-close # server端可關閉HTTP連接的功能；
option forwardfor except 127.0.0.0/8 # 傳遞client端的IP地址給server端，並寫入“X-Forward_for”首部中；
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 30000
listen stats
mode http
bind 0.0.0.0:1080 # 統計頁面綁定1080端口；
stats enable # 開啓統計頁面功能；
stats hide-version # 隱藏Haproxy版本號；
stats uri /haproxyadmin?stats # 自定義統計頁面的訪問uri；
stats realm Haproxy\ Statistics # 統計頁面密碼驗證時的提示信息；
stats auth admin:admin # 爲統計頁面開啓登錄驗證功能；
stats admin if TRUE # 若登錄用戶驗證通過，則賦予管理功能；
frontend http-in
bind *:80
mode http
log global
option httpclose
option logasap
option dontlognull
capture request header Host len 20
capture request header Referer len 60
acl url_static path_beg -i /static /images /javascript /stylesheets
acl url_static path_end -i .jpg .jpeg .gif .png .css .js .html
use_backend static_servers if url_static # 符合ACL規則的，請求轉入後端靜態服務器
default_backend dynamic_servers # 默認請求轉入後端動態服務器
backend static_servers
balance roundrobin
server imgsrv1 192.168.0.25:80 check maxconn 6000 # 靜態服務器，可配置多臺，還可設置權重weight；
backend dynamic_servers
balance source # 對於動態請求利用source調度算法，可一定程度上實現session保持；但最好利用cookie綁定的方式實現session保持
server websrv1 192.168.0.35:80 check maxconn 1000 # 動態服務器，可配置多臺，還可設置權重weight；啓動服務
service haproxy start # 兩節點都需要啓動
Nginx部署
見博客“如何測試Nginx的高性能”
訪問驗證
Haproxy統計頁面測試
動靜分離測試
高可用測試
