keepalived:
Linux Cluster
LB: lvs, nginx
HA：keepalived, heartbeat, corosync, cman
HP：
分佈式存儲：HDFS
分佈式計算：YARN,
batch: MapReduce
in-memory: spark
stream: storm
keepalived：
Acitve/Passive
lvs: vip, ipvs rules
nginx: vip, nginx service
resource, 高可用資源
HA Service: resources
ntp: network time protocol
vrrp：virtual route redundent protocol
Master/Backup
keepalived：
vrrp協議在Linux主機上以守護進程方式的實現；
能夠根據配置文件自動生成ipvs規則；
對各RS做健康狀態檢測；
組件：
vrrp stack
checkers
ipvs wrapper --> ipvs
配置文件的組成部分：
GLOBAL CONFIGURATION
VRRPD CONFIGURATION
vrrp instance
vrrp synchonization group
LVS CONFIGURATION
HA Cluster配置前提：
1、本機的主機名，要與hostname(uname -n)獲得的名稱保持一致；
CentOS 6: /etc/sysconfig/network
CentOS 7: hostnamectl set-hostname HOSTNAME
各節點要能互相解析主機名；一般建議通過hosts文件進行解析；
2、各節點時間同步；
3、確保iptables及selinux不會成爲服務阻礙；
virtual_ipaddress {
<IPADDR>/<MASK> brd <IPADDR> dev <STRING> scope <SCOPE> label <LABEL>
192.168.200.17/24 dev eth1
192.168.200.18/24 dev eth2 label eth2:1
}
nopreempt：非搶佔模式；默認爲搶佔模式；
lvs-NAT模式配置
vrrp_sync_group VG_1 {
group {
VI_1 # name of vrrp_instance (below)
VI_2 # One for each moveable IP.
}
}
vrrp_instance VI_1 {
eth0
vip
}
vrrp_instance VI_2 {
eth1
dip
}
郵件通知方式：
在vi中的主機狀態發生改變生髮送通知：
# notify scripts, alert as above
notify_master <STRING>|<QUOTED-STRING>
notify_backup <STRING>|<QUOTED-STRING>
notify_fault <STRING>|<QUOTED-STRING>
notify <STRING>|<QUOTED-STRING>
smtp_alert
配置示例：
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from kaadmin@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_mcast_group4 224.0.1.118
}
vrrp_script chk_mt {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface eno16777736
virtual_router_id 144
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 84ae57f7f4f6
}
virtual_ipaddress {
172.16.100.88/16 dev eno16777736 label eno16777736:1
}
track_script {
chk_mt
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 172.16.100.88 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.0.0
protocol TCP
sorry_server 127.0.0.1 80
real_server 172.16.100.6 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 172.16.100.69 80 {
weight 2
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
通知腳本：
#!/bin/bash
# Author: zhanx <[email protected]>
# description: An example of notify script
#
vip=172.16.100.88
contact='root@localhost'
notify() {
mailsubject="`hostname` to be $1: $vip 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
exit 0
;;
backup)
notify backup
exit 0
;;
fault)
notify fault
exit 0
;;
*)
echo 'Usage: `basename $0` {master|backup|fault}'
exit 1
;;
esac
keepalived：
HTTP_GET
SSL_GET(https)
TCP_CHECK
示例：
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
TCP_CHECK {
connect_timeout 3
}
HA Services:
nginx