nginx負載均衡+keepalived高可用完全配置小結
nginx做負載均衡（無高可用）
大致步驟。
1. 前端
nginx安裝，pcre安裝，具體步驟不解釋。
2. 負載配置
A. 預設輪循
在nginx.conf 里加入一行
include upstream.conf,然後所有的負載均衡的配置直接在upstream.conf裡配置。
[[email protected] conf]# cat upstream.conf
upstream httpservers {
server 192.168.137.10:80 weight=5;
server 192.168.137.20:80 weight=5;
}
server {
listen 80;
server_name 192.168.137.100;
location / {
proxy_pass http://httpservers;
}
}
A. ip_hash每個請求按訪問ip的hash結果分配，這樣每個訪客固定訪問一個後端伺服器，可以解決session的問題
[[email protected] conf]# cat upstream.conf
upstream httpservers {
ip_hash;
server 192.168.137.10:80 weight=5;
server 192.168.137.20:80 weight=5;
}
server {
listen 80;
server_name 192.168.137.100;
location / {
proxy_pass http://httpservers;
}
}
nginx做負載均衡（keepalived高可用）
拓撲圖
1. nginx配置（在主備伺服器上配置）
upstream httpservers {
ip_hash;
server 192.168.137.10:80 weight=5;
server 192.168.137.20:80 weight=5;
}
server {
listen 80;
server_name 192.168.137.201;
location / {
proxy_pass http://httpservers;
}
}
2. keepalived安裝及配置（在主備伺服器上配置）
下載：wget http://www.keepalived.org/software/keepalived-1.2.8.tar.gz
解壓：tar zxvf keepalived-1.2.8.tar.gz
編譯安裝： ./configure --prefix=/usr/local/keepalived
make
make install
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d
cp /usr/local/keepalived/sbin/keepalived /sbin/
mkdir -p /etc/keepalived/
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ (配置檔案一定要在這裡，讓我費了好大的勁)
修改/etc/keepalived/keepalived.conf , 以下分別列出master和backup的配置
+++++++++++++++++++++++++++++++++++++master+++++++++++++++++++++++++++++++++++++++++++
! Configuration File for keepalived
global_defs {
router_id nginx-proxy-ha
}
vrrp_script chk_http_port {
script "/usr/bin/check_nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 200
advert_int 1
authentication {
auth_type PASS
auth_pass 1234
}
track_interface {
eth0
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.137.201
}
}
++++++++++++++++++++++++backup++++++++++++++++++++++++++++++++++++++++++++++++++
! Configuration File for keepalived
global_defs {
router_id nginx-proxy-ha
}
vrrp_script chk_http_port {
script "/usr/bin/check_nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 180
advert_int 1
authentication {
auth_type PASS
auth_pass 1234
}
track_interface {
eth0
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.137.201
}
}
以上配置完成之後 啟動nginx和keepalived，一定要先啟動nginx，然後在啟動keepalived。
測試效果：master和backup都啟動keepalived和nginx後，預設的虛擬ip是在master上的，在master上kill nginx後，浮動ip會繫結在backup上。
各配置解釋：
global_defs {
notification_email {
[email protected] (這裡可以定義多個報警郵箱)
}
notification_email_from [email protected] (報警人)
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/opt/tools/bin/check_ng.sh"
interval 2 （檢測指令碼執行的間隔）
weight 2
}
vrrp_instance VI_1 {
state BACKUP （顯示定義為從伺服器）
interface eth1 （繫結的網口，該網口即上面提到的兩個IP的介面）
virtual_router_id 51 （定義的ID，官方的是 51，主從伺服器必須一直）
mcast_src_ip 211.151.138.3 （從伺服器的IP）
priority 50 （優先順序，任意定義，但是一定要比主伺服器低）
advert_int 1
authentication {
auth_type PASS
auth_pass 1111 （預設即可）
}
track_script {
chk_http_port （呼叫檢測指令碼）
}
virtual_ipaddress {
211.151.137.5 （繫結的虛IP）
}
}
++++++++++++++++++++++check_nginx.sh+++++++++++++++++++++++++++++++++++++++++++++++++
該指令碼用來檢測nginx狀態，一旦nginx退出，則關閉master的 keepalived，此時的backup收到訊息會自動切換為master並繫結虛擬ip。該指令碼放在/usr/bin下
#!/bin/bash
if [ "$(ps -ef | grep "nginx: master process"| grep -v grep )" == "" ]
then
killall -9 keepalived
fi
轉載於:https://blog.51cto.com/flyingdreams/1535155